Induction of alkaline phosphatase in the inflamed intestine: a novel pharmacological target for inflammatory bowel disease

The correlation between serum alkaline phosphatase and grip strength in middle-aged and elderly people: NHANES 2011-2014

BACKGROUND

Serum alkaline phosphatase (ALP) plays a crucial role in bone and muscle health. Previous studies have demonstrated that serum alkaline phosphatase (ALP) is closely associated with muscle mass. Nevertheless, the association between serum alkaline phosphatase (ALP) and grip strength remains unclear. Therefore, the present study focused on exploring the association of serum ALP with grip strength in middle-aged and elderly people.

METHODS

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey conducted from 2011 to 2014. A total of 3514 participants (1891 males and 1623 females) aged 40-80 years were included in this study. Serum ALP and pelvic grip strength were analyzed as independent and dependent variables, additional variables were the possible impact modifiers. weighted generalized linear models and stratified analysis by gender, age group, and race were applied to assess the relationship between serum ALP and grip strength. Smooth curve fitting and threshold effect analysis/saturation effect analysis were used to analyze the nonlinear relationship between the 2 variables.

RESULTS

In the gender-stratified subgroup analysis, we observed an inverse association between serum ALP and grip strength in both male and female. When stratified by age group, the association remained significant among participants 40-59 years of age, but not among those ≥ 60 years old. When stratified by race, the association remained significant among Non-Hispanic White and Non-Hispanic Black. It is noteworthy that serum ALP and grip strength showed a significant negative correlation among female aged 40-59 years, but not among female aged ≥ 60 years. Additionally, Smooth curve fitting showed that serum ALP had a nonlinear relationship with grip strength in male aged 40-59 years and male aged over 60 years, the inflection points are 54 IU and 97 IU respectively.

CONCLUSION

Our study revealed an inverse relationship between serum ALP and grip strength, this finding offers new insights and avenues for understanding how serum alkaline phosphatase affects skeletal muscle health.

Comparison of blood parameters in two genetically different groups of horses for functional longevity in show jumping

Introduction

In order to find early selection criteria to improve the longevity of show jumping horses, a specific protocol was designed.

Methods

Before entering competition, young horses selected from extreme stallions for longevity were measured for many traits, including blood parameters. Blood samples were taken from 952 horses aged 2-4 years old, sired by two groups of stallions: one with unfavorable (U) and the other with favorable (F) extreme estimated breeding values for functional longevity. These breeding values were previously calculated from data on 202,320 horses that participated in show jumping competitions between 1985 and 2022. Functional longevity was defined as time spent in competition, adjusted for the level of performance. The 59 measured parameters included hematology, proteins, cytokines, liver and kidney function, bone and joint health, oxidative stress and endocrinology. Heritability was estimated using a mixed model that accounted for the effect of age, sex, estimated weight, visit (place and date of collection), and animal random additive value with 10,280 horses in pedigree. A Partial Least Square logistic regression was performed to predict the sire group.

Results

Age, sex and estimated weight significantly affected 36, 19 and 16 variables, respectively. The visit had a significant effect on all variables. Heritability estimates were high, with 75% higher than 0.20% and 30% higher than 0.50. The most heritable traits included mean corpuscular volume (0.92, se 0.11), mean corpuscular hemoglobin (0.90, se 0.11), white blood cells (0.55, se 0.13), total alkaline phosphatase (0.68, se 0.12) and percentage of γ-globulin (0.57, se 0.12). The logistic regression that predicted the group of sires favorable for longevity identified 16 significant variables. Key findings included: lower mean corpuscular hemoglobin (p-value < 0.001), lower mean corpuscular volume (p-value < 0.001), lower number of white blood cells (p-value < 0.01), higher percentage of intestinal and bone alkaline phosphatase (p-value < 0.01) for a lower total alkaline phosphatase (p-value < 0.01), higher percentage of α2-globulin (p-value < 0.001) and lower percentage of β1-globulin (p-value < 0.01).

Discussion

Blood parameters measured at rest in young horses may be predictive of their genetic value for functional longevity in show jumping.

Pectin Modulates Calcium Absorption in Polarized Caco-2 Cells via a Pathway Distinct from Vitamin D Stimulation

Pectin, a type of soluble fiber, promotes morphological changes in the small intestinal villi. Although its physiological significance is unknown, we hypothesized that changes in villus morphology enhance the efficiency of nutrient absorption in the small intestine and investigated the effect of pectin derived from persimmon on calcium absorption using polarized Caco-2 cells. In polarized Caco-2 cells, pectin altered the mRNA expression levels of substances involved in calcium absorption and the regulation of intracellular calcium concentration and significantly reduced calcium absorption. Although this was comparable to the results of absorption and permeability associated with the addition of active vitamin D, the simultaneous action of pectin and active vitamin D did not show any additive effects. Furthermore, as active vitamin D significantly increases the activity of intestinal alkaline phosphatase (ALP), which is known to be involved in the regulation of intestinal absorption of calcium and lipids, we also investigated the effect of pectin on intestinal ALP activity. As a result, it was found that, unlike the effect of active vitamin D, pectin significantly reduced intestinal ALP activity. These results suggest that pectin stimulates polarized Caco-2 cells through a mechanism distinct from the regulation of calcium absorption by vitamin D, modulating total calcium absorption from the elongated villi through morphological changes in the small intestine by suppressing it at the cellular level.

Redox Proteomic Profile of Tirapazamine-Resistant Murine Hepatoma Cells

3-Amino-1,2,4-benzotriazine-1,4-dioxide (tirapazamine, TPZ) and other heteroaromatic N-oxides (ArN→O) exhibit tumoricidal, antibacterial, and antiprotozoal activities. Their action is attributed to the enzymatic single-electron reduction to free radicals that initiate the prooxidant processes. In order to clarify the mechanisms of aerobic mammalian cytotoxicity of ArN→O, we derived a TPZ-resistant subline of murine hepatoma MH22a cells (resistance index, 5.64). The quantitative proteomic of wild-type and TPZ-resistant cells revealed 5818 proteins, of which 237 were up- and 184 down-regulated. The expression of the antioxidant enzymes aldehyde- and alcohol dehydrogenases, carbonyl reductases, catalase, and glutathione reductase was increased 1.6-5.2 times, whereas the changes in the expression of glutathione peroxidase, superoxide dismutase, thioredoxin reductase, and peroxiredoxins were less pronounced. The expression of xenobiotics conjugating glutathione-S-transferases was increased by 1.6-2.6 times. On the other hand, the expression of NADPH:cytochrome P450 reductase was responsible for the single-electron reduction in TPZ and for the 2.1-fold decrease. These data support the fact that the main mechanism of action of TPZ under aerobic conditions is oxidative stress. The unchanged expression of intranuclear antioxidant proteins peroxiredoxin, glutaredoxin, and glutathione peroxidase, and a modest increase in the expression of DNA damage repair proteins, tend to support non-site-specific but not intranuclear oxidative stress as a main factor of TPZ aerobic cytotoxicity.

Identification and genetic analysis of major gene ST3GAL4 related to serum alkaline phosphatase in chicken

Alkaline phosphatase (ALP) is a marker of osteoblast maturation and an important indicator of bone metabolism. The activity of ALP can reflect the bone metabolism and growth traits of animals, so the polymorphism affecting ALP expression deserves further study. In this study, we identified an SNP site in ST3GAL4 found by genome-wide association studies (GWAS) in previous studies, 8 SNPs were also identified by DNA sequencing. Interestingly, there were 4 SNPs (rs475471G > A, rs475533C > T, rs475621A > G, rs475647C > A) completely linked by haplotype analysis. Therefore, we selected a tag SNP rs475471G > A to further analyze the ALP level of different genotypes in Hubbard leg disease population and an F₂ chicken resource population produced by Anka and Gushi chickens and carried out population genetic analysis in 18 chicken breeds. Association analysis showed that this QTL within ST3GAL4 was highly correlated with ALP level. The mutant individuals with genotype AA had the highest ALP level, followed by GA and GG carriers. The mutant individual carriers of AA and GA genotype had higher values for body weight (BW), chest width (CW), body slanting length (BSL), pelvis width (PW) at 4-week, the semi-evisceration weight (SEW), evisceration weight (EW) and Leg weight (LW) than GG genotypes. The amplification and typing of 4852 DNA samples from 18 different breeds showed GG genotype mainly existed in egg-type chickens and dual-type chickens, while the AA genotype was mainly distributed in commercial broilers and F₂ resource population. The individual carriers of the AA genotype had the highest ALP and showed better growth performance. Besides, tissue expression analysis used Cobb broiler showed significant differences between different genotypes in the spleen and duodenum. Taken together, this was the first time to determine 9 SNPs within ST3GAL4 related to ALP in chickens, 4 of them were complete linkage with each other, which provides useful information on the mutation of ST3GAL4 and could predict the serum ALP level of chicken early and as an effective potential molecular breeding marker for chickens.

Sinigrin Attenuates the Dextran Sulfate Sodium-induced Colitis in Mice by Modulating the MAPK Pathway

Ulcerative colitis (UC) is an intestinal inflammatory disease characterised by the loss of intestinal crypts, edema, mucosal ulceration, and infiltration of inflammatory cells in the mucosa. The current study aimed to investigate the protective and therapeutic effects of sinigrin and underlying mechanisms in a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis. DSS-induced colitis models were used to demonstrate sinigrin's therapeutic/protective action. Mice were orally administered with sinigrin (15 mg/kg or 30 mg/kg) for a period of 12 days in both prophylactic and therapeutic models. Animal weights, stool consistency, and bleeding parameters were measured throughout the experimental period. After the experimental period, colon lengths were measured, and colon tissues were harvested to determine the levels of oxidative stress-inducing factors (nitrates and MDA levels) and anti-oxidant components (GSH, SOD, and catalase). Furthermore, gene expression analysis, IL-17 levels, and inflammatory marker expressions were measured using RT-qPCR, ELISA, and immunohistochemical methods respectively. Furthermore, histopathological observations and elucidation of the mechanism of action were determined using H&E analysis and Western blot analysis. Sinigrin treatment (in both prophylactic and therapeutic models) significantly mitigated the DSS-induced body weight loss, attenuated the colon length shrinkage, and improved the disease index score (p < 0.001). Further results revealed that sinigrin's protective/therapeutic effect is associated with a significant attenuation of pro‑inflammatory cytokine production (p < 0.001), reversing the anti-oxidant enzyme levels (p < 0.001) and substantial improvement (2 folds) of the disruption of the colonic morphology in colon tissues compared to DSS control. Immunohistochemical analysis showed that sinigrin treatment remarkably reduced the DSS-induced myeloperoxidase, neutrophil elastase, and CD68 expression in colon tissues. Additionally, sinigrin successfully abrogated the DSS-induced IL-17 levels (p < 0.001) and improved the colonic barrier in colon tissues. Overall, these results demonstrated that sinigrin exerts protective and therapeutic effects on DSS‑induced colitis, by enhancing the anti-oxidant enzymes and suppressing the intestinal inflammatory cascade of markers by regulating the MAPK pathway.

Effect of a Single and Triple Dose of Levamisole on Hematological Parameters in Controlled Inflammation Model

This study aimed to evaluate the impact of single and triple administration of levamisole on the dynamics of hematological parameters during experimental pleuritis. The experiment was performed on female Buffalo rats. Rats were randomly assigned to two equal groups that received 1 and 3 doses of levamisole every 2, 24 and 48 h, respectively. Following the experiment, blood samples for the measurement of hematological parameters were collected. The study group receiving three doses of levamisole observed a significant reduction of red blood cell count at 48 h post administration and an increase in mean corpuscular volume compared to the control inflammation group. The administration of a single dose of levamisole results in a significant increase in hematocrit at 72 h, an increase in white blood cell count at 24 h and 72 h, and an increase in neutrophil count at 72 h compared to the control inflammation group. Administration of a single and triple dose of levamisole showed statistically significant modification of some hematological parameters and thus modulates the inflammatory process. In the lungs, this results in a reduction in leukocyte infiltrations around the bronchi and blood vessels.

Systematic Oxidative Stress Indexes Associated with the Prognosis in Patients with T Lymphoblastic Lymphoma/Leukemia

Background

T lymphoblastic lymphoma/leukemia (T-LBL/ALL) is an aggressive malignant tumor with 5-year overall survival (OS) rate reached 80% after high-dose chemotherapy. Due to the relatively low incidence of T-LBL/ALL, only a few risk factors have been identified. The occurrence and prognosis of malignant tumors are closely related to oxidative stress, but the prognostic relationship between T-LBL/ALL and systematic oxidative stress indexes has not been reported yet.

Methods

A total of 258 T-LBL/ALL patients were retrospectively analyzed. The relationship between systematic oxidative stress indexes, such as creatinine (CRE), gamma-glutamyl transpeptidase (γ-GGT), albumin (ALB), alkaline phosphatase (ALP), fibrinogen (FBG), C-reactive protein (CRP) and total bilirubin (TBIL), and survival of T-LBL/ALL patients, was analyzed. The weight of indexes was used to calculate the patients' oxidative stress risk score. The independent prognostic value of oxidative stress risk grouping (OSRG) was analyzed.

Results

Higher CRE, CRP, and lower ALB were associated with poorer OS in T-LBL/ALL patients. The OSRG established by CRE, ALB, and CRP was an independent prognostic factor for OS of T-LBL/ALL patients. Patients in the high-risk group were more likely to be patients older than 14 years old and patients with superior vena cava obstruction syndrome (SVCS), pleural effusion, pericardial effusion, and mediastinal mass.

Conclusion

For OS in T-LBL/ALL patients, OSRG was observed as an independent prognostic factor, which provided a new idea for accurate prognostic prediction.

Single-Molecule Biosensing of Alkaline Phosphatase in Cells and Serum Based on Dephosphorylation-Triggered Catalytic Assembly and Disassembly of the Fluorescent DNA Chain

Alkaline phosphatase (ALP) is a valuable biomarker and effective therapeutic target for the diagnosis and treatment of diverse human diseases, including bone disorder, cardiovascular disease, and cancers. The reported ALP assays often suffer from laborious procedures, costly reagents, inadequate sensitivity, and large sample consumption. Herein, we report a new single-molecule fluorescent biosensor for the simple and ultrasensitive detection of ALP. In this assay, the ALP-catalyzed dephosphorylation of detection probe can protect the detection probe against lambda exonuclease-mediated digestion, and the remaining detection probes can trigger ceaseless hybridization between two Cy5-labeled hairpin probes through toehold-mediated DNA strand displacement, generating a long fluorescent DNA chain, which can be subsequently separated from unhybridized hairpin probes and disassembled into dispersed Cy5 moieties upon NaOH treatment. The free Cy5 moieties indicate the presence of ALP and can be directly quantified via single-molecule counting. This biosensor enables efficient amplification and transduction of the target ALP signal through enzyme-free assembly and disassembly processes, significantly simplifying the experimental procedure and improving the assay accuracy. The proposed biosensor allows specific and ultrasensitive detection of ALP activity with a detection limit down to 2.61 × 10^-6 U mL^-1 and is suitable for ALP inhibition assay and kinetic analysis. Moreover, this biosensor can be applied for endogenous ALP detection in human cells and clinical human serum, holding the potential in the ALP biological function study and clinical diagnosis.

Ileal alkaline phosphatase is upregulated following functional amino acid supplementation in Salmonella Typhimurium-challenged pigs

We recently showed that functional amino acid (FAA) supplementation improves growth performance and immune status of Salmonella Typhimurium (ST)-challenged pigs, which was further improved by a longer adaptation period. It is expected that the effects are associated with increased activity of intestinal alkaline phosphatase (IAP). The objective of this study was to evaluate the effects of FAA supplementation and adaptation period on the ileal, cecal, and colonic activity of IAP in weaned pigs challenged with ST. In experiment 1, a total of 32 mixed-sex weanling pigs were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement with low (LP) or high protein (HP) content and basal (FAA-) or FAA profile (FAA+; Thr, Met, and Trp at 120% of requirements) as factors. In experiment 2, a total of 32 mixed-sex weanling pigs were randomly assigned to one of four dietary treatments, being FAA- fed throughout the experimental period (FAA-) or an FAA profile fed only in the post-inoculation (FAA + 0), for 1 wk pre- and post-inoculation (FAA + 1), or throughout the experimental period (FAA + 2). In experiments 1 and 2, after a 7- and 14-d adaptation period, respectively, pigs were inoculated with saline solution containing ST (3.3 and 2.2 × 109 CFU/mL, respectively). Plasma alkaline phosphatase was measured on days 0 and 7 post-inoculation in experiment 1, and IAP (ileum, cecum, and colon) was measured in experiments 1 and 2. Correlations among ileal IAP and serum albumin and haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), and reduced:oxidized glutathione, ileal myeloperoxidase, ST shedding and ileal colonization, and post-inoculation average daily gain, feed intake (ADFI), and gain:feed were also analyzed. In experiment 1, plasma alkaline phosphatase was decreased with ST inoculation and the overall content was increased in LP-FAA+ compared with LP-FAA- (P < 0.05). Moreover, ileal IAP was increased in FAA+ compared with FAA- pigs in both studies (P < 0.05) regardless of adaptation time (P > 0.05). IAP was positively correlated with MDA and ADFI and negatively correlated with SOD and ST shedding in experiment 1 (P < 0.05). These results demonstrate a positive effect of FAA supplementation, but not adaptation period, on ileal alkaline phosphatase activity in Salmonella-challenged pigs, which may be associated with improvements in antioxidant balance.

Mice carrying an epithelial deletion of the glucocorticoid receptor NR3C1 develop a higher tumor load in experimental colitis-associated cancer

The glucocorticoid receptor NR3C1 is expressed in multiple cell types in the gut and elsewhere. Intestinal epithelial cells both produce and respond to glucocorticoids in different physiological and pathological contexts. In experimental colitis, glucocorticoids have been shown to exert a dual role, dampening inflammation while producing a deterioration in animal status, including death. Mice with tamoxifen-inducible, intestinal epithelial-specific deletion of NR3C1 (NR3C1^ΔIEC mice) are protected against experimental colitis, suggesting glucocorticoid epithelial actions are deleterious. Since glucocorticoids modulate epithelial proliferation, it follows that they may affect the development of colon cancer. In this study, we set out to test this hypothesis using the dextran sulfate sodium-azoxymethane model of colitis-associated cancer. Knockout (KO) mice were found to exhibit a twofold higher tumor load but similar incidence and tumor size. Tumors had a higher trend to extend close to the submucosal layer (36% vs. 0%) in NR3C1^ΔIEC mice, and overexpressed Lgr5, Egfr, and Myc, consistent with distinct expression of proliferative/stemness markers. Snai1 and Snai2 were upregulated specifically in tumors of NR3C1^ΔIEC mice, suggesting enhanced epithelial to mesenchymal transition in the absence of the intestinal epithelial glucocorticoid (GC) receptor. We conclude that endogenous GC epithelial signaling is involved in colitis-associated cancer.NEW & NOTEWORTHY Mice carrying a tamoxifen-inducible deletion of the glucocorticoid receptor in intestinal epithelial cells (NR3C1^ΔIEC mice) and their corresponding controls were subjected to the azoxymethane-dextran sulfate sodium model of colitis-associated cancer. KO mice exhibit a twofold higher tumor load, with a higher trend to extend close to the submucosal layer (36% vs. 0%), but with similar incidence and tumor size. Colonic tumors in NR3C1^ΔIEC mice showed signs of increased neoplastic transformation and tumor-associated inflammation.

Deficiency in Tissue Non-Specific Alkaline Phosphatase Leads to Steatohepatitis in Mice Fed a High Fat Diet Similar to That Produced by a Methionine and Choline Deficient Diet

The liver expresses tissue-nonspecific alkaline phosphatase (TNAP), which may participate in the defense against bacterial components, in cell regulation as part of the purinome or in bile secretion, among other roles. We aimed to study the role of TNAP in the development of hepatosteatosis. TNAP^+/− haplodeficient and wild type (WT) mice were fed a control diet (containing 10% fat w/w) or the same diet deficient in methionine and choline (MCD diet). The MCD diet induced substantial weight loss together with hepatic steatosis and increased alanine aminotransferase (ALT) plasma levels, but no differences in IL-6, TNF, insulin or resistin. There were no substantial differences between TNAP^+/− and WT mice fed the MCD diet. In turn, TNAP^+/− mice receiving the control diet presented hepatic steatosis with alterations in metabolic parameters very similar to those induced by the MCD diet. Nevertheless, no weight loss, increased ALT plasma levels or hypoglycemia were observed. These mice also presented increased levels of liver TNF and systemic resistin and glucagon compared to WT mice. The phenotype of TNAP^+/− mice fed a standard diet was normal. In conclusion, TNAP haplodeficiency induces steatosis comparable to that produced by a MCD diet when fed a control diet.

Novel Dietary Proteins Selectively Affect Intestinal Health In Vitro after Clostridium difficile-Secreted Toxin A Exposure

Bacterial gastroenteritis forms a burden on a global scale, both socially and economically. The Gram-positive bacterium Clostridium difficile is an inducer of gastrointestinal bacterial infections, often triggered following disruption of the microbiota by broad-spectrum antibiotics to treat other conditions. The clinical manifestatiaons, e.g., diarrhea, are driven by its toxins secretion, toxin A (TcdA) and toxin B (TcdB). Current therapies are focused on discontinuing patient medication, including antibiotics. However, relapse rates upon therapy are high (20-25%). Here, eighteen dietary proteins were evaluated for their capacity to restore gut health upon C. difficile-derived TcdA exposure. We used bioengineered intestinal tubules to assess proteins for their beneficial effects by examining the epithelial barrier, cell viability, brush-border enzyme activity, IL-6 secretion, IL-8 secretion and nitric oxide (NO) levels upon TcdA challenge. TcdA effectively disrupted the epithelial barrier, increased mitochondrial activity, but did not affect alkaline phosphatase activity, IL-6, IL-8 and NO levels. Intervention with dietary proteins did not show a protective effect on epithelial barrier integrity or mitochondrial activity. However, bovine plasma and potato protein increased alkaline phosphatase activity, egg-white protein increased IL-6 and IL-8 release and wheat, lesser mealworm and yeast protein increased NO levels after TcdA exposure. Hence, dietary proteins can influence parameters involved in intestinal physiology and immune activation suggesting that supplementation with specific dietary proteins may be of benefit during C. difficile infections.

Synthesis and computational studies of highly selective inhibitors of human recombinant tissue non-specific alkaline phosphatase (h-TNAP): A therapeutic target against vascular calcification

In this study, we have discovered small druglike molecules as selective inhibitors of human tissue-nonspecific alkaline phosphatase (h-TNAP), an enzyme critical for the regulation of extracellular matrix calcification. The upregulation of h-TNAP is associated with various pathologies particularly the vascular calcification (VC). Selective inhibition of h-TNAP over h-NPP1 may serve as a useful therapeutic strategy against vascular calcification. A series of novel triazolyl pyrazole derivatives (10a-y) in which thiol bearing triazole moiety as the zinc binding functional group was introduced to a pyrazole based pharmacophore was synthesized and evaluated as potent and selective inhibitors of h-TNAP over h-NPP1. The biological screening against h-TNAP, h-IAP, h-NPP1 and h-NPP3 showed that many of the synthesized compounds are selective inhibitors of TNAP. Particularly, the compounds 10a-h, 10j, 10m-q, 10u, 10w and 10x displayed high potency and complete selectivity towards h-TNAP over h-NPP1. Compound 10q emerged as a highly potent inhibitor (IC₅₀ = 0.16 µM or 160 nM) against h-TNAP with 127-fold increased inhibition compared to levamisole. On the other hand, compound 10e was found to be most selective inhibitor against the tested APs and NPPs (IC₅₀ = 1.59 ± 0.36 µM). Binding sites architecture analysis, molecular-docking and molecular dynamics simulations (MDS), revealed the basis for h-TNAP and h-IAP ligand selectivity as well as selectivity towards h-TNAP over h-NPP1. These newly discovered inhibitors are believed to represent valuable lead structures to further streamline the generation of candidate compounds to target VC.

Correlations between the Peptide Hormone Ghrelin and Proinflammatory Cytokines in Experimental Periodontitis Models of Female Rats at Different Stages of the Life Cycle

OBJECTIVE

The aim of this study was to examine the correlations between the levels of ghrelin and inflammatory and bone metabolism markers in rats with periodontitis.

DESIGN

Thirty female Wistar rats (6 trial rats and 4 control rats in each group) were divided into pubertal, adult and postmenopausal groups. Periodontitis was induced by ligatures. On the 21 st day, blood was collected and all rats were then sacrificed. The levels of osteocalcin, osteoprotegerin, alkaline phosphatase, tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), acylated ghrelin, total ghrelin and soluble receptor activator of nuclear factor-kB ligands in the blood samples were measured using enzyme-linked immunosorbent assays. The jaws were decalcified in a Tris-EDTA solution and embedded in paraffin and 4-5 μm sections were cut for IL-β, TNF -α and ghrelin staining.

RESULTS

Significantly higher serum alkaline phosphatase levels were detected in the trial rats in the pubertal group than in the control rats (p = 0.033). In the postmenopausal group, ghrelin levels positively correlated with interleukin 1 beta levels (r = 0.708, p < 0.05). Among all trial rats, the postmenopausal group exhibited significantly higher levels of acylated ghrelin than the other groups (p = 0.001). Significantly higher osteoprotegerin levels were observed in the control rats than in the trial rats in the postmenopausal group (p = 0.012). Inflammation scores were significantly higher in adult trial rats than in controls (p = 0.024); significantly higher TNF-α levels were detected in postmenopausal experimental rats than in the adult experimental group (p = 0.025).

CONCLUSIONS

We concluded that total ghrelin levels in serum only correlated with IL-β levels in postmenopausal rats.

Lower expression of endogenous intestinal alkaline phosphatase may predict worse prognosis in patients with Crohn's disease

BACKGROUNDS

Intestinal alkaline phosphatase (IAP) plays important role in gut homeostasis. We aimed to evaluate the expression of endogenous IAP and to assess the clinical course according to the expression of endogenous IAP in patients with Crohn's disease (CD).

METHODS

A total of 32 consecutive patients (14 males) with CD were included in the study. We measured the level of endogenous iAP in inflamed and noninflamed colonic mucosa. To verify the inflammation status, we measured the level of mRNA for IL-6, TNF-α, and TLR-4. We monitored the clinical courses of patients during follow-up after acquisition of biopsy specimens.

RESULTS

Median age of patients was 22.5 years (range, 15-49). Median CD activity index (CDAI, range) was 93.7 (22.8~ 154.9). There were colonic involvements in all patients and perianal involvement in 43.8% patients. The mRNA levels of IL-6 (p = 0.005) and TLR-4 (p = 0.013) in inflamed mucosa were significantly higher than those in non-inflamed mucosa. However, there was no difference of expression of TNF-α mRNA (p = 0.345). During a 14-month follow-up (range, 9 months-54 months), there were 19 patients with clinical recurrences. There were 9 patients (9/19, 47.4%) with IAP expression ratio (inflamed to non-inflamed) ≤ 1.0 in patients with clinical recurrence while there was one patient (1/13, 7.7%) with IAP ratio ≤ 1.0 in patients without clinical recurrence (p = 0.024).

CONCLUSION

Lower expression of IAP in inflamed mucosa compared to non-inflamed mucosa may be associated with clinical recurrence in patients with CD.

Local level of TGF-β1 determines the effectiveness of dexamethasone through regulating the balance of Treg/Th17 cells in TNBS-induced mouse colitis

Transforming growth factor β1 (TGF-β1) has a crucial role in regulating the balance of type 17 T-helper cells (Th17) and T regulatory cells (Tregs) that are involved in the pathogenesis of inflammatory bowel disease, while the function of local TGF-β1 in this process has remained to be fully elucidated. The present study investigated the effects of different local TGF-β1 levels on the Treg/Th17 balance and on the dexamethasone efficacy in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Various TGF-β1 levels in colon tissue were achieved by enema delivery of a high, medium or low amount of adenovirus expressing TGF-β1 (10⁷, 10⁸ or 10⁹ pfu, denoted as AdTGF-1, AdTGF-2 and AdTGF-3, respectively). Dexamethasone further decreased colon damage and myeloperoxidase activity in TNBS mice receiving AdTGF-1 and AdTGF-2. When AdTGF-1 was administered, dexamethasone enhanced its effect by reducing interferon (IFN)-γ and increasing interleukin (IL)-10 production. In TNBS mice receiving AdTGF-2, the increase in IFN-γ, tumor necrosis factor-α, IL-6, IL-17 and IL-23 was significantly prevented by dexamethasone treatment. In comparison with the lower doses, AdTGF-3 exerted the opposite effect on regulating the cytokine production in TNBS mice, which was not affected by dexamethasone treatment. In mesenteric lymph nodes, AdTGF-1 prevented the TNBS-induced reduction of Tregs and IL-10, and potentially increased the efficacy of dexamethasone. In addition, dexamethasone further decreased the levels of activated caspase3 in TNBS mice receiving adenoviral TGF-β1, particularly in the AdTGF-1 group. The activation of the p38 mitogen-activated protein kinase/c-Jun N-terminal kinase/c-Jun pathway was significantly inhibited by a low amount of TGF-β1 administered to TNBS-treated mice, which was further decreased by dexamethasone. The present study provided evidence that the therapeutic effect of dexamethasone may depend on the local levels of TGF-β1 in TNBS-induced colitis and may be mediated, at least partially, through promoting the differentiation of Tregs and thus altering the balance of pro- and anti-inflammatory cytokines.

Comparison of anti-inflammatory activities of an anthocyanin-rich fraction from Portuguese blueberries (Vaccinium corymbosum L.) and 5-aminosalicylic acid in a TNBS-induced colitis rat model

Despite the actual therapeutic approaches for inflammatory bowel disease (IBD), efficient and secure alternative options remain a research focus. In this context, anthocyanins seem promising natural anti-inflammatory agents, but their action mechanisms and efficacy as compared with established drugs still require more clarification. The main aim of this study was to compare the anti-inflammatory action of a chemically characterized anthocyanin-rich fraction (ARF), obtained from Portuguese blueberries (Vaccinium corymbosum L.), with that of 5-aminosalicylic acid (5-ASA), a first-line drug in IBD, in a 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis rat model. Such fraction showed a high content and great molecular diversity of anthocyanins, with malvidin-3-galactoside and petunidin-3-arabinoside in the highest concentrations. After daily administration by intragastric infusion for 8 days, ARF, at a molar anthocyanin concentration about 30 times lower than 5-ASA, showed a higher effectiveness in counteracting the intestinal inflammation, as assessed by i) body weight variation and colon damage score, ii) reduction in leukocyte infiltration, iii) increase in antioxidant defenses and iv) by downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in colon tissue homogenates. The strong inhibition of COX-2 expression seems to be a crucial anti-inflammatory mechanism common to both ARF and 5-ASA, but the additional higher abilities of anthocyanins to downregulate iNOS and to decrease leukocytes infiltration and to increase antioxidant defenses in colon may account for the much higher anti-inflammatory action of anthocyanins. These data may contribute to the development of a promising natural approach in IBD management.

The Role of Intestinal Alkaline Phosphatase in Inflammatory Disorders of Gastrointestinal Tract

Over the past few years, the role of intestinal alkaline phosphatase (IAP) as a crucial mucosal defence factor essential for maintaining gut homeostasis has been established. IAP is an important apical brush border enzyme expressed throughout the gastrointestinal tract and secreted both into the intestinal lumen and into the bloodstream. IAP exerts its effects through dephosphorylation of proinflammatory molecules including lipopolysaccharide (LPS), flagellin, and adenosine triphosphate (ATP) released from cells during stressful events. Diminished activity of IAP could increase the risk of disease through changes in the microbiome, intestinal inflammation, and intestinal permeability. Exogenous IAP exerts a protective effect against intestinal and systemic inflammation in a variety of diseases and represents a potential therapeutic agent in diseases driven by gut barrier dysfunction such as IBD. The intestinal protective mechanisms are impaired in IBD patients due to lower synthesis and activity of endogenous IAP, but the pathomechanism of this enzyme deficiency remains unclear. IAP has been safely administered to humans and the human recombinant form of IAP has been developed. This review was designed to provide an update in recent research on the involvement of IAP in intestinal inflammatory processes with focus on IBD in experimental animal models and human patients.

Germ-free and Antibiotic-treated Mice are Highly Susceptible to Epithelial Injury in DSS Colitis

BACKGROUND AND AIMS

Intestinal microbiota is required to maintain immune homeostasis and intestinal barrier function. At the same time, intraluminal bacteria are considered to be involved in inflammatory bowel disease and are required for colitis induction in animal models, with the possible exception of dextran sulphate sodium [DSS] colitis. This study was carried out to ascertain the mechanism underlying the induction of colitis by DSS in the absence of bacteria.

METHODS

Conventional and germ-free [GF] Naval Medical Research Institute [NMRI] mice were used, plus conventional mice treated with an antibiotic cocktail to deplete the intestinal microbiota ['pseudo-GF' or PGF mice]. The differential response to DSS was assessed.

RESULTS

Conventional mice developed DSS-induced colitis normally, whereas GF mice showed only minimal inflammation [no colonic thickening, lower myeloperoxidase activity, IL-6, IL-17, TNF-α, and IFN-γ secretion by splenocytes and mesenteric cell cultures, etc.]. However, these mice suffered enhanced haemorrhage, epithelial injury and mortality as a consequence of a weakened intestinal barrier, as shown by lower occludin, claudin 4, TFF3, MUC3, and IL-22. In contrast, PGF mice had a relatively normal, albeit attenuated, inflammatory response, but were less prone to haemorrhage and epithelial injury than GF mice. This was correlated with an increased expression of IL-10 and Foxp3 and preservation barrier-related markers.

CONCLUSIONS

We conclude that enteric bacteria are essential for the development of normal DSS-induced colitis. The absence of microbiota reduces DSS colonic inflammation dramatically but it also impairs barrier function, whereas subtotal microbiota depletion has intermediate effects at both levels.

Radiation-induced changes in intestinal and tissue-nonspecific alkaline phosphatase: implications for recovery after radiation therapy

BACKGROUND

Exogenous replacement of depleted enterocyte intestinal alkaline phosphatase (IAP) decreases intestinal injury in models of colitis. We determined whether radiation-induced intestinal injury could be mitigated by oral IAP supplementation and the impact on tissue-nonspecific AP.

METHODS

WAG/RjjCmcr rats (n = 5 per group) received lower hemibody irradiation (13 Gy) followed by daily gavage with phosphate-buffered saline or IAP (40 U/kg/d) for 4 days. Real-time polymerase chain reaction, AP activity, and microbiota analysis were performed on intestine. Lipopolysaccharide and cytokine analysis was performed on serum. Data were expressed as a mean ± SEM with P greater than .05 considered significant.

RESULTS

Intestine of irradiated animals demonstrates lower hemibody irradiation and is associated with upregulation of tissue-nonspecific AP, downregulation of IAP, decreased AP activity, and altered composition of the intestinal microbiome.

CONCLUSIONS

Supplemental IAP after radiation may be beneficial in mitigating intestinal radiation syndrome as evidenced by improved histologic injury, decreased acute intestinal inflammation, and normalization of intestinal microbiome.

Fructooligosaccharides exert intestinal anti-inflammatory activity in the CD4+ CD62L+ T cell transfer model of colitis in C57BL/6J mice

PURPOSE

Fructooligosaccharides (FOS) are used as functional foods due to their prebiotic effects. Intestinal anti-inflammatory activity has been established in most, but not all, studies in animal models of colitis, using mainly chemically induced inflammation. Our goal was to test the effect of FOS (degree of polymerization 2-8) in the chronic, lymphocyte-driven CD4+ CD62L+ T cell transfer model of colitis.

METHODS

Colitis was induced by transfer of CD4+ CD62L+ T cells to C57BL/6J Rag1(-/-) mice. FOS (75 mg day(-1)) was administered by gavage as a post-treatment. Three groups were established: non-colitic (NC), colitic control (C, CD4+ CD62L+ transferred mice treated with vehicle) and colitic+FOS (C+FOS, similar but treated with FOS). Mice were killed after 13 days.

RESULTS

Treatment of mice with FOS ameliorated colitis, as evidenced by an increase in body weight, a lesser myeloperoxidase and alkaline phosphatase activities, a lower secretion of proinflammatory cytokines by mesenteric lymph node cells ex vivo (IFN-γ, IL-17, and TNF-α), and a higher colonic expression of occludin (C+FOS vs. C, p < 0.05). Increased relative abundance of lactic acid bacteria was observed in FOS-treated mice (p < 0.05).

CONCLUSIONS

FOS exert intestinal anti-inflammatory activity in T lymphocyte-dependent colitis, suggesting it may be useful in the management of inflammatory bowel disease in appropriate conditions.

Inflammatory bowel disease therapies discontinued between 2009 and 2014

INTRODUCTION

New therapeutic approaches are currently under development, which consider the fundamental mechanisms involved in the pathogenesis of inflammatory bowel disease (IBD). The disease is associated with inflamed intestinal and colonic mucosa in response to the dysregulated immune system.

AREAS COVERED

The aim of this article is to review drugs that have been designed for the treatment of IBD and discontinued between 2009 and 2014. Herein, nine molecules with different mechanisms of action are under review. Brodalumab, daclizumab, elubrixin and vatelizumab were withdrawn from the Phase II trial due to the lack of efficacy. Abatacept was not significantly superior to the placebo in the rate of remission and its Phase III trials were stopped. CNDO-210 and Catridecacog were discontinued due to safety concerns and lack of efficacy, respectively. Finally, NU-206 and alkaline phosphatase also ceased in development during Phase I and II tests.

EXPERT OPINION

The development in our knowledge and understanding of the pathophysiology of IBD and the identification of key objectives for the future play significant roles in IBD therapeutic development. Furthermore, well-planned clinical trials with concise measures of efficacy and safety are required to better decide whether to extend or terminate the development process. Some anti-inflammatory cytokines such as IL-2, IL-12, IL-17, IL-18, IL-23 and INF-γ could garner more attention in the future.

Intestinal anti-inflammatory activity of apigenin K in two rat colitis models induced by trinitrobenzenesulfonic acid and dextran sulphate sodium

Flavonoids are polyphenolic compounds that are widespread in nature, and consumed as part of the human diet in significant amounts. The aim of the present study was to test the intestinal anti-inflammatory activity of apigenin K, a soluble form of apigenin, in two models of rat colitis, namely the trinitrobenzenesulfonic acid (TNBS) model and the dextran sulphate sodium (DSS) model. Apigenin K (1, 3 and 10 mg/kg; by the oral route; n 4-6 per group) was administered as a pre-treatment to rats with TNBS and DSS colitis, and colonic status was checked by macroscopic and biochemical examination. Apigenin K pre-treatment resulted in the amelioration of morphological signs and biochemical markers in the TNBS model. The results demonstrated a reduction in the inflamed area, as well as lower values of score and colonic weight:length ratio compared with the TNBS group. Myeloperoxidase (MPO) activity was reduced by 30 % (P< 0·05). Moreover, apigenin K pre-treatment ameliorated morphological signs and biochemical markers in the DSS model. Thus, macroscopic damage was significantly reduced and the colonic weight:length ratio was lowered by approximately 10 %, while colonic MPO and alkaline phosphatase activities were decreased by 35 and 21 %, respectively (P< 0·05). Apigenin K pre-treatment also tended to normalise the expression of a number of colonic inflammatory markers (e.g. TNF-α, transforming growth factor-β, IL-6, intercellular adhesion molecule 1 or chemokine (C-C motif) ligand 2). In conclusion, apigenin K is found to have anti-inflammatory effects in two preclinical models of inflammatory bowel disease.

Rutin has intestinal antiinflammatory effects in the CD4+ CD62L+ T cell transfer model of colitis

Rutin, one of the most abundant flavonoids in nature, has been shown to exert intestinal antiinflammatory effects in experimental models of colitis. Our aim was to study the antiinflamatory effect of rutin in the CD4+ CD62L+ T cell transfer model of colitis, one of the closest to the human disease. Colitis was induced by transfer of CD4+ CD62L+ T cells to Rag1(-/-) mice. Rutin was administered by gavage as a postreatment. Treatment with rutin improved colitis at the dose of 57mg/kg/day, while no effect was noted with 28.5mg/kg/day. Therapeutic benefit was evidenced by a reduced disease activity index, weight loss and damage score, plus a 36% lower colonic myeloperoxidase and a 54% lower alkaline phosphatase activity. In addition, a decreased secretion of proinflammatory cytokines (IFNγ and TNFα) by mesenteric lymph node cells was observed ex vivo. The colonic expression of proinflammatory genes, including IFNγ, TNFα, CXCL1, S100A8 and IL-1β, was significantly reduced by more than 80% with rutin as assessed by RT-qPCR. Flavonoid treated mice exhibited decreased activation of splenic CD4+ cells (STAT4 phosphorylation and IFNγ expression) and reduced plasma cytokine levels. This effect was also apparent in mucosal lymphocytes based on reduced STAT4 phosphorylation. The protective effect was comparable to that of 3mg/kg/day budesonide. Rutin had no effect on splenocytes or murine T cells in vitro, while its aglycone, quercetin, exhibited a concentration dependent inhibition of proinflammatory cytokines, including IFNγ. Rutin but not quercetin showed vectorial basolateral to apical transport in IEC18 cells, associated with reduced biotransformation. We conclude that rutin exerts intestinal antiinflammatory activity in chronic, T lymphocyte dependent colitis via quercetin release and actions involving mucosal and lymph node T cells. Our results suggest that rutin may be useful in the management of inflammatory bowel disease in appropriate dosage conditions.

In vitro impact of five pesticides alone or in combination on human intestinal cell line Caco-2

In Burkina Faso, as in most Sahelian countries, the failure to follow good agricultural practices coupled with poor soil and climate conditions in the locust control context lead to high environmental contaminations with pesticide residues. Thus, consumers being orally exposed to a combination of multiple pesticide residues through food and water intake, the digestive tract is a tissue susceptible to be directly exposed to these food contaminants. The aim of our work was to compare in vitro the impact of five desert locust control pesticides (Deltamethrin DTM, Fenitrothion FNT, Fipronil FPN, Lambda-cyalothrine LCT, and Teflubenzuron TBZ) alone and in combination on the human intestinal Caco-2 cells viability and function. Cells were exposed to 0.1–100 μM pesticides for 10 days alone or in mixture (MIX). Our results showed a cytotoxic effect of DTM, FNT, FPN, LCT, and TBZ alone or in combination in human intestinal Caco-2 cells. The most efficient were shown to be FPN and FNT impacting the cell layer integrity and/or barrier function, ALP activity, antioxidant enzyme activity, lipid peroxidation, Akt activation, and apoptosis. The presence of antioxidant reduced lipid peroxidation level and attenuated the pesticides-induced cell toxicity, suggesting that key mechanism of pesticides cytotoxicity may be linked to their pro-oxidative potential. A comparative analysis with the predicted cytotoxic effect of pesticides mixture using mathematical modeling shown that the combination of these pesticides led to synergistic effects rather than to a simple independent or dose addition effect.

Oral exposure to the organophosphorus insecticide, Monocrotophos induces intestinal dysfunction in rats

There is limited experimental evidence to imply the role of organophosphorus insecticides on intestinal dysfunctions. Residues of Monocrotophos (MCP), above maximum residue limits (MRL), have been reported in fruits and vegetables from various parts of India. Hence, in this study, we investigated the potential of MCP to induce intestinal dysfunction in rats. MCP was administered orally to rats at sublethal doses (0.45, 0.9 and 1.8 mg/kgb.w/d) for 30 days. MCP at the highest dose significantly increased the unit weight of the small intestine. MCP increased the activities of intestinal brush border disaccharidases, intestinal alkaline phosphatase, glycyl-glycine dipeptidase, and Na(+)/K(+)-ATPase while it decreased cholesterol: phospholipid ratio. Histology and scanning electron microscopy of small intestine of MCP treated rats revealed disruption in terms of congestion, increased length of villi, goblet cell hyperplasia, infiltration of inflammatory cells and necrotic villi tip. Further, the intestinal transit rate was found to be increased in MCP treated rats. Collectively, our findings provide evidence that repeated oral intake of MCP has the propensity to alter small intestinal structure and functions, which might lead to intestinal dysfunctions and abnormal nutrient uptake and thereby affect the human health. Although we have employed doses, which are higher than those likely to be encountered as residues, we speculate that further studies should be performed to determine whether MCP residues in foods in the long-term will interfere with the digestive capacity of the small intestine and thus exert adverse effects on the health of human.

Antioxidant and intestinal anti-inflammatory effects of plant-derived coumarin derivatives

BACKGROUND

Coumarins, also known as benzopyrones, are plant-derived products with several pharmacological properties, including antioxidant and anti-inflammatory activities. Based on the wide distribution of coumarin derivatives in plant-based foods and beverages in the human diet, our objective was to evaluate both the antioxidant and intestinal anti-inflammatory activities of six coumarin derivatives of plant origin (scopoletin, scoparone, fraxetin, 4-methyl-umbeliferone, esculin and daphnetin) to verify if potential intestinal anti-inflammatory activity was related to antioxidant properties.

METHODS

Intestinal inflammation was induced by intracolonic instillation of TNBS in rats. The animals were treated with coumarins by oral route. The animals were killed 48 h after colitis induction. The colonic segments were obtained after laparotomy and macroscopic and biochemical parameters (determination of glutathione level and myeloperoxidase and alkaline phosphatase activities) were evaluated. The antioxidant properties of these coumarins were examined by lipid peroxidation and DPPH assays.

RESULTS

Treatment with esculin, scoparone and daphnetin produced the best protective effects. All coumarin derivatives showed antioxidant activity in the DPPH assay, while daphnetin and fraxetin also showed antioxidant activity by inhibiting lipid peroxidation. Coumarins, except 4-methyl-umbeliferone, also showed antioxidant activity through the counteraction of glutathione levels or through the inhibition of myeloperoxidase activity.

DISCUSSION

The intestinal anti-inflammatory activity of coumarin derivatives were related to their antioxidant properties, suggesting that consumption of coumarins and/or foods rich in coumarin derivatives, particularly daphnetin, esculin and scoparone, could prevent intestinal inflammatory disease.

Effect of glucans from Caripia montagnei mushroom on TNBS-induced colitis

In this study, we evaluated the effect of different doses of polysaccharides extracted from Caripia montagnei mushroom at different intervals of treatment on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). The FT-IR analysis and NMR showed that the polysaccharides from this species of mushroom are composed of α- and β-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed the reduction of colonic lesions in all groups treated with the glucans. Such glucans significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that the glucans from C. montagnei acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01) and myeloperoxidase (p < 0.001), a result confirmed by the reduction of cellular infiltration observed microscopically. The increase of catalase activity possibly indicates a protective effect of these glucans on colonic tissue, confirming their anti-inflammatory potential.

Hymenaea stigonocarpa Mart. ex Hayne: A tropical medicinal plant with intestinal anti-inflammatory activity in TNBS model of intestinal inflammation in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Stem bark and fruit pulp of Hymenaea stigonocarpa Mart ex. Hayne (Fabaceae) has been popularly used to treat inflammation and gastrointestinal diseases including ulcers, diarrhea and gastric pain. The aim of this study was to investigate the intestinal anti-inflammatory activity of a methanol extract derived from the stem bark and diet with fruit pulp of Hymenaea stigonocarpa in the TNBS model of intestinal inflammation in rats.

MATERIAL AND METHODS

The intestinal anti-inflammatory activity of stem bark extract (100, 200 and 400mg/kg) and fruit pulp (10% and 5% in diet) was measured against the intestinal inflammatory process induced by TNBS (trinitrobenzesulphonic acid) in rats. The protective effects were evaluated as follows: evaluation of intestinal damage (damage score, extension of lesion, colon weight/length ratio), incidence of diarrhea and adherence to adjacent organs, colon glutathione (GSH) and malondialdehyde (MDA) contents, myeloperoxidase (MPO) and alkaline phosphatase (AP) activities. In addition, in vitro studies on lipid peroxidation in rat brain membranes and phytochemical profile were performed with both stem bark and fruit pulp.

RESULTS

Treatment with 100, 200 and 400mg/kg of stem bark extract and 10% fruit pulp flour showed protective effects in the TNBS-induced colon damage, which was related to inhibition of MPO and AP activities, reduction in colon MDA content, and counteraction of GSH depletion induced by inflammatory process. A concentration-dependent inhibitory effect on the lipid peroxidation in rat brain membranes for stem bark and fruit pulp was determined, with an IC50 value of 5.25 ± 0.23 μg/mL and 27.33 ± 0.09 μg/mL, respectively. Similar phytochemical composition was observed in fruit and stem bark, including mainly flavonoids, condensed tannins and terpenes.

CONCLUSIONS

Stem bark extract and fruit pulp flour of Hymenaea stigonocarpa prevented TNBS-induced colonic damage in rats and this protective effect were associated to an improvement of intestinal oxidative stress. The observed anti-inflammatory and antioxidant effects may be associated to the presence of flavonoids and tannins in the stem bark and fruit pulp of Hymenaea stigonocarpa.

Gut pathology and responses to the microsporidium Nosema ceranae in the honey bee Apis mellifera

The microsporidium Nosema ceranae is a newly prevalent parasite of the European honey bee (Apis mellifera). Although this parasite is presently spreading across the world into its novel host, the mechanisms by it which affects the bees and how bees respond are not well understood. We therefore performed an extensive characterization of the parasite effects at the molecular level by using genetic and biochemical tools. The transcriptome modifications at the midgut level were characterized seven days post-infection with tiling microarrays. Then we tested the bee midgut response to infection by measuring activity of antioxidant and detoxification enzymes (superoxide dismutases, glutathione peroxidases, glutathione reductase, and glutathione-S-transferase). At the gene-expression level, the bee midgut responded to N. ceranae infection by an increase in oxidative stress concurrent with the generation of antioxidant enzymes, defense and protective response specifically observed in the gut of mammals and insects. However, at the enzymatic level, the protective response was not confirmed, with only glutathione-S-transferase exhibiting a higher activity in infected bees. The oxidative stress was associated with a higher transcription of sugar transporter in the gut. Finally, a dramatic effect of the microsporidia infection was the inhibition of genes involved in the homeostasis and renewal of intestinal tissues (Wnt signaling pathway), a phenomenon that was confirmed at the histological level. This tissue degeneration and prevention of gut epithelium renewal may explain early bee death. In conclusion, our integrated approach not only gives new insights into the pathological effects of N. ceranae and the bee gut response, but also demonstrate that the honey bee gut is an interesting model system for studying host defense responses.

Exogenous alkaline phosphatase treatment complements endogenous enzyme protection in colonic inflammation and reduces bacterial translocation in rats

Alkaline phosphatase (AP) inactivates bacterial lipopolysaccharide and may therefore be protective. The small intestine and colon express intestinal (IAP) and tissue nonspecific enzyme (TNAP), respectively. The aim of this study was to assess the therapeutic potential of exogenous AP and its complementarity with endogenous enzyme protection in the intestine, as evidenced recently. IAP was given to rats by the oral or intrarectal route (700U/kgday). Oral budesonide (1mg/kgday) was used as a reference treatment. Treatment with intrarectal AP resulted in a 54.5% and 38.0% lower colonic weight and damage score, respectively, and an almost complete normalization of the expression of S100A8, LCN2 and IL-1β (p<0.05). Oral AP was less efficacious, while budesonide had a more pronounced effect on most parameters. Both oral and intrarectal AP counteracted bacterial translocation effectively (78 and 100%, respectively, p<0.05 for the latter), while budesonide failed to exert a positive effect. AP activity was increased in the feces of TNBS colitic animals, associated with augmented sensitivity to the inhibitor levamisole, suggesting enhanced luminal release of this enzyme. This was also observed in the mouse lymphocyte transfer model of chronic colitis. In a separate time course study, TNAP was shown to increase 2-3 days after colitis induction, while dextran sulfate sodium was a much weaker inducer of this isoform. We conclude that exogenous AP exerts beneficial effects on experimental colitis, which includes protection against bacterial translocation. AP of the tissue-nonspecific isoform is shed in higher amounts to the intestinal lumen in experimental colitis, possibly aiding in intestinal protection.

Dietary intervention with narrow-leaved cattail rhizome flour (Typha angustifolia L.) prevents intestinal inflammation in the trinitrobenzenesulphonic acid model of rat colitis

Background

Inflammatory bowel disease (IBD) is a chronic inflammation of the intestinal epithelium that is driven by the intestinal immune system, oxidative stress and the loss of tolerance to the luminal microbiota. The use of dietary products containing ingredients such as fibres and carbohydrates and/or antioxidant compounds have been used as a therapeutic strategy for intestinal diseases because these products are considered effective in the modulation of the immune system and colonic microbiota. We investigated the beneficial effects of cattail rhizome flour (Typha angustifolia L.) in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. In addition, we investigated the effects of cattail rhizome flour on the intestinal anti-inflammatory activity of prednisolone, which is a reference drug that is used for treatment of human IBD.

Methods

The present study included the preparation of flour from rhizomes of cattail (Typha angustifolia L.); an evaluation of the qualitative phytochemical profile of cattail rhizomes; an evaluation of the efficacy of cattail rhizome flour in TNBS-induced rat colitis; an evaluation of the synergistic effects of cattail rhizome flour on the intestinal anti-inflammatory activity of prednisolone; and macroscopic, clinical, biochemical, histopathological and microbiological studies to assess the healing effects of cattail rhizome flour and its synergistic effects in TNBS-induced rat colitis. The data were analysed by ANOVA, Kruskal-Wallis and χ² tests.

Results

We tested several concentrations of cattail rhizome flour and found that dietary supplementation with 10% cattail rhizome flour showed the best effects at reducing the extension of the lesion, the colon weight ratio, adherences to adjacent organs and diarrhoea. These effects were related to inhibition of myeloperoxidase (MPO) and alkaline phosphatase (AP) activities and an attenuation of glutathione (GSH) depletion. The 10% cattail rhizome flour was as effective as prednisolone, and no synergistic effects were observed. Saponins, flavonoids and coumarins were detected in the rhizome flour. No changes were observed in the total number of lactic bacteria after dietary supplementation with cattail rhizome flour.

Conclusions

Dietary supplementation with 10% cattail rhizome flour and its combination with prednisolone prevent TNBS-induced colonic damage in rats, but no synergistic effects were observed. The prevention of TNBS-induced colon damage was associated with an improvement in intestinal oxidative stress, which likely resulted from the antioxidant properties of the active compounds detected in the cattail rhizome. This protective effect was not related to an improvement in lactic bacteria counts.

Experimental model of heterotopic ossification in Wistar rats

Heterotopic ossification (HO) is a metaplastic biological process in which there is newly formed bone in soft tissues adjacent to large joints, resulting in joint mobility deficit. In order to determine which treatment techniques are more appropriate for such condition, experimental models of induced heterotopic bone formation have been proposed using heterologous demineralized bone matrix implants and bone morphogenetic protein and other tissues. The objective of the present experimental study was to identify a reliable protocol to induce HO in Wistar rats, based on autologous bone marrow (BM) implantation, comparing 3 different BM volumes and based on literature evidence of this HO induction model in larger laboratory animals. Twelve male Wistar albino rats weighing 350/390 g were used. The animals were anesthetized for blood sampling before HO induction in order to quantify serum alkaline phosphatase (ALP). HO was induced by BM implantation in both quadriceps muscles of these animals, experimental group (EG). Thirty-five days after the induction, another blood sample was collected for ALP determination. The results showed a weight gain in the EG and no significant difference in ALP levels when comparing the periods before and after induction. Qualitative histological analysis confirmed the occurrence of heterotopic ossification in all 12 EG rats. In conclusion, the HO induction model was effective when 0.35 mL autologous BM was applied to the quadriceps of Wistar rats.

Growth and Development Symposium: Endotoxin, inflammation, and intestinal function in livestock

Endotoxin, also referred to as lipopolysaccharide (LPS), can stimulate localized or systemic inflammation via the activation of pattern recognition receptors. Additionally, endotoxin and inflammation can regulate intestinal epithelial function by altering integrity, nutrient transport, and utilization. The gastrointestinal tract is a large reservoir of both gram-positive and gram-negative bacteria, of which the gram-negative bacteria serve as a source of endotoxin. Luminal endotoxin can enter circulation via two routes: 1) nonspecific paracellular transport through epithelial cell tight junctions, and 2) transcellular transport through lipid raft membrane domains involving receptor-mediated endocytosis. Paracellular transport of endotoxin occurs through dissociation of tight junction protein complexes resulting in reduced intestinal barrier integrity, which can be a result of enteric disease, inflammation, or environmental and metabolic stress. Transcellular transport, via specialized membrane regions rich in glycolipids, sphingolipids, cholesterol, and saturated fatty acids, is a result of raft recruitment of endotoxin-related signaling proteins leading to endotoxin signaling and endocytosis. Both transport routes and sensitivity to endotoxin may be altered by diet and environmental and metabolic stresses. Intestinal-derived endotoxin and inflammation result in suppressed appetite, activation of the immune system, and partitioning of energy and nutrients away from growth toward supporting the immune system requirements. In livestock, this leads to the suppression of growth, particularly suppression of lean tissue accretion. In this paper, we summarize the evidence that intestinal transport of endotoxin and the subsequent inflammation leads to decrease in the production performance of agricultural animals and we present an overview of endotoxin detoxification mechanisms in livestock.