Deferiprone-Gallium-Protoporphyrin Chitogel Decreases Pseudomonas aeruginosa Biofilm Infection without Impairing Wound Healing.

Pseudomonas aeruginosa is one of the most common pathogens encountered in clinical wound infections. Clinical studies have shown that P. aeruginosa infection results in a larger wound area, inhibiting healing, and a high prevalence of antimicrobial resistance. Hydroxypyridinone-derived iron chelator Deferiprone (Def) and heme analogue Gallium-Protoporphyrin (GaPP) in a chitosan-dextran hydrogel (Chitogel) have previously been demonstrated to be effective against PAO1 and clinical isolates of P. aeruginosa in vitro. Moreover, this combination of these two agents has been shown to improve sinus surgery outcomes by quickly reducing bleeding and preventing adhesions. In this study, the efficacy of Def-GaPP Chitogel was investigated in a P. aeruginosa biofilm-infected wound murine model over 6 days. Two concentrations of Def-GaPP Chitogel were investigated: Def-GaPP high dose (10 mM Def + 500 µg/mL GaPP) and Def-GaPP low dose (5 mM Def + 200 µg/mL GaPP). The high-dose Def-GaPP treatment reduced bacterial burden in vivo from day 2, without delaying wound closure. Additionally, Def-GaPP treatment decreased wound inflammation, as demonstrated by reduced neutrophil infiltration and increased anti-inflammatory M2 macrophage presence within the wound bed to drive wound healing progression. Def-GaPP Chitogel treatment shows promising potential in reducing P. aeruginosa cutaneous infection with positive effects observed in the progression of wound healing.

Emu Oil and zinc monoglycerolate independently reduce disease severity in a rat model of ulcerative colitis.

Ulcerative colitis is characterized by colonic inflammation. Previously, Emu Oil protected the intestine against experimentally-induced inflammatory intestinal disorders. Zinc monoglycerolate (ZMG) polymer, formed by heating zinc oxide with glycerol, demonstrated anti-inflammatory and wound healing properties. We aimed to determine whether ZMG, alone or in combination with Emu Oil, could reduce acute colitis severity in rats. Male Sprague Dawley rats (n = 8/group) were orally-administered either vehicle, ZMG, Emu Oil (EO) or ZMG combined with EO (ZMG/EO) daily. Rats were provided ad libitum access to drinking water (Groups 1-4) or dextran sulphate sodium (DSS; 2%w/v; Groups 5-8) throughout the trial (days 0-5) before euthanasia on day 6. Disease activity index, crypt depth, degranulated mast cells (DMCs) and myeloperoxidase (MPO) activity were assessed. p < 0.05 was considered significant. DSS increased disease severity (days 3-6) compared to normal controls (p < 0.05). Importantly, in DSS-administered rats, ZMG/EO (day 3) and ZMG (day 6) reduced disease activity index compared to controls (p < 0.05). Following DSS consumption, distal colonic crypts lengthened (p < 0.01), occurring to a greater extent with EO compared to ZMG and ZMG/EO (p < 0.001). DSS increased colonic DMC numbers compared to normal controls (p < 0.001); an effect decreased only by EO (p < 0.05). Colonic MPO activity increased following DSS consumption (p < 0.05); notably, ZMG, EO and ZMG/EO treatments decreased MPO activity compared to DSS controls (p < 0.001). EO, ZMG and ZMG/EO did not impact any parameter in normal animals. Emu Oil and ZMG independently decreased selected indicators of colitic disease severity in rats; however, the combination did not reveal any additional benefit.

Negative consequences of reduced protein diets supplemented with synthetic amino acids for performance, intestinal barrier function, and caecal microbiota composition of broiler chickens.

The consequences of feeding broiler chickens with reduced protein (RP) diets for gut health and barrier function are not well understood. This study was performed to elucidate the effect of reducing dietary protein and source of protein on gut health and performance parameters. Four experimental diets included 2 control diets with standard protein levels either containing meat and bone meal (CMBM) or an all-vegetable diet (CVEG), a medium RP diet (17.5% in growers and 16.5% in finisher), and a severe RP diet (15.6% in grower and 14.6% in finisher). Off-sex Ross 308 birds were assigned to each of the 4 diets and performance measurements were taken from d 7 to 42 post-hatch. Each diet was replicated 8 times (10 birds per replicate). A challenge study was conducted on additional 96 broilers (24 birds per diet) from d 13 to 21. Half of the birds in each dietary treatment were challenged by dexamethasone (DEX) to induce a leaky gut. Feeding birds with RP diets decreased weight gain (P < 0.0001) and increased feed conversion ratio (P < 0.0001) from d 7 to 42 compared with control diets. There was no difference between CVEG and CMBM control diets for any parameter. The diet containing 15.6% protein increased (P < 0.05) intestinal permeability independent of the DEX challenge. Gene expression of claudin-3 was downregulated (P < 0.05) in birds fed 15.6% protein. There was a significant interaction between diet and DEX (P < 0.05) and both RP diets (17.5% and 15.6%) downregulated claudin-2 expression in DEX-challenged birds. The overall composition of the caecal microbiota was affected in birds fed 15.6% protein having a significantly lower richness of microbiota in both sham and DEX-injected birds. Proteobacteria was the main phylum driving the differences in birds fed 15.6% protein. At the family level, Bifidobacteriaceae, Unclassified Bifidobacteriales, Enterococcaceae, Enterobacteriaceae, and Lachnospiraceae were the main taxa in birds fed 15.6% protein. Despite supplementation of synthetic amino acids, severe reduction of dietary protein compromised performance and intestinal health parameters in broilers, evidenced by differential mRNA expression of tight junction proteins, higher permeability, and changes in caecal microbiota composition.

Thermoregulation during Field Exercise in Horses Using Skin Temperature Monitoring.

Hyperthermia and exertional heat illness (EHI) are performance and welfare issues for all exercising horses. Monitoring the thermoregulatory response allows for early recognition of metabolic heat accumulation during exercise and the possibility of taking prompt and effective preventative measures to avoid a further increase in core body temperature (Tc) leading to hyperthermia. Skin temperature (Tsk) monitoring is most used as a non-invasive tool to assess the thermoregulatory response pre- and post-exercise, particularly employing infrared thermographic equipment. However, only a few studies have used thermography to monitor skin temperature continuously during exercise. This commentary provides an overview of studies investigating surface skin temperature mainly by infrared thermography (IRT) during exercise. The scientific evidence, including methodologies, applications, and challenges associated with (continuous) skin temperature monitoring in horses during field exercise, is discussed. The commentary highlights that, while monitoring Tsk is straightforward, continuous Tsk alone does not always reliably estimate Tc evolvement during field exercise. In addition, inter-individual differences in thermoregulation need to be recognized and accounted for to optimize individual wellbeing. With the ongoing development and application of advanced wearable monitoring technology, there may be future advances in equipment and modeling for timely intervention with horses at hyperthermic risk to improve their welfare. However, at this point, infrared thermographic assessment of Tsk should always be used in conjunction with other clinical assessments and veterinary examinations for a reliable monitoring of the welfare of the horse.

Is Continuous Monitoring of Skin Surface Temperature a Reliable Proxy to Assess the Thermoregulatory Response in Endurance Horses During Field Exercise?

Hyperthermia is a performance and welfare issue for exercising horses. The thermoregulatory stressors associated with exercise have typically been estimated by responses in the laboratory. However, monitoring surface skin temperature (T sk ) coincident with core temperature (T c ) has not previously been investigated in horses exercising in the field. We investigated the suitability of monitoring surface T sk as a metric of the thermoregulatory response, and simultaneously investigated its relationship with T c using gastrointestinal (GI) temperature. We evaluated T sk in 13 endurance horses competing during four endurance rides over 40 km (n = 1) or a total of 80 km (n = 12) distance. Following each 40-km loop, the horses were rested for 60 min. T sk and T c were continuously recorded every 15 s by an infrared thermistor sensor located in a modified belt and by telemetric GI pill, respectively, and expressed as mean ± SD. The net area under the curve (AUC) was calculated to estimate the thermoregulatory response to the thermal load of T sk over time (°C × minutes) using the trapezoidal method. The relationship between T sk and T c was assessed using scatterplots, paired t-test or generalized linear model ANOVA (delta T sk ) (n = 8). Ambient temperature ranged from 6.7°C to 18.4°C. No relationship was found between T sk and T c profiles during exercise and recovery periods, and no significant difference between delta T sk results was detected when comparing exercise and rest. However, time to maximum T sk (67 min) was significantly reduced compared to T c (139 min) (p = 0.0004) with a significantly lesser maximum T sk (30.3°C) than T c (39°C) (p = 0.0002) during exercise. Net AUC T sk was 1,164 ± 1,448 and -305 ± 388°C × minutes during periods of exercise and recovery, respectively. We conclude that T sk monitoring does not provide a reliable proxy for the thermoregulatory response and horse welfare, most probably because many factors can modulate T sk without directly affecting T c . Those factors, such as weather conditions, applicable to all field studies can influence the results of T sk in endurance horses. The study also reveals important inter-individual differences in T sk and T c time profiles, emphasizing the importance of an individualized model of temperature monitoring.

Emu Oil Attenuates Disease Severity and Results in Fewer Large Colonic Tumors in a Mouse Model of Colitis-Associated Colorectal Cancer.

Ulcerative colitis patients have an increased risk of developing colorectal cancer (CRC). The aim of the current study was to determine whether Emu Oil (EO) could reduce the severity of colitis, thereby inhibiting colitis-associated CRC (CA-CRC) development. Female C57BL/6 mice (n = 8/group) were injected (i.p.) with saline or azoxymethane (AOM) (7.4 mg/kg). Mice underwent three dextran sulfate sodium (DSS)/water cycles. Mice were orally-administered either water (160 µL) or EO (80 µL or 160 µL) thrice weekly and euthanized after 12 weeks. AOM/DSS decreased bodyweight compared with normal controls (max. 20%; p < 0.05). In AOM/DSS mice, EO (160 µL) increased bodyweight compared with untreated and 80 µL EO-treated mice (max. 10%; p < 0.05). Both volumes of EO reduced disease activity index (DAI) scores on day 49, 56-63 (max. 40%; p < 0.05), compared with AOM/DSS controls. Histological damage was increased in the distal colon of AOM/DSS mice, and reduced by EO (160 µL; p < 0.05). Mucin-secreting goblet cells were increased by AOM/DSS compared to normal, with no effect observed following EO treatment (p > 0.05). Large tumor numbers were decreased in EO-treated mice (160 µL; 2 ± 0.6) compared with AOM/DSS controls (5 ± 0.7; p < 0.05). EO did not impact overall tumor number (p > 0.05). Other analyses remained unchanged across groups (p > 0.05). EO demonstrates promise as an adjunct to conventional treatment options for colitis management.

Continuous Monitoring of the Thermoregulatory Response in Endurance Horses and Trotter Horses During Field Exercise: Baselining for Future Hot Weather Studies.

Establishing proper policies regarding the recognition and prevention of equine heat stress becomes increasingly important, especially in the face of global warming. To assist this, a detailed view of the variability of equine thermoregulation during field exercise and recovery is essential. 13 endurance horses and 12 trotter horses were equipped with continuous monitoring devices [gastrointestinal (GI) pill, heartrate (HR) monitor, and global positioning system] and monitored under cool weather conditions during four endurance rides over a total of 80 km (40 km loops) and intense trotter track-based exercise over 1,540 m. Recordings included GI temperature (T c ), speed, HR and pre- and post-exercise blood values. A temperature time profile curve of T c was constructed, and a net area under the curve was calculated using the trapezoidal method. Metabolic heat production and oxygen cost of transport were also calculated in endurance horses. Maximum T c was compared using an independent samples t-test. Endurance horses (mean speed 14.1 ± 1.7 km h-1) reached mean maximum T c (39.0 ± 0.4°C; 2 × 40 km in 8 horses) during exercise at 75% of completion of T c exercise and T c returned to baseline within 60 min into recovery. However, the mean T c was still 38.8 ± 0.4°C at a HR of 60 bpm which currently governs "fit to continue" competition decisions. Trotters (40.0 ± 2.9 km h-1) reached a comparable mean max T c (38.8 ± 0.5°C; 12 horses) always during recovery. In 30% of trotters, T c was still >39°C at the end of recovery (40 ± 32 min). The study shows that horses are individuals and thermoregulation monitoring should reflect this, no matter what type of exercise is performed. Caution is advised when using HR cut-off values to monitor thermal welfare in horses since we have demonstrated how T c can peak quite some time after finishing exercise. These findings have implications for training and management of performance horses to safeguard equine welfare and to maximize performance.

Emu Oil and Saireito in combination reduce tumour development and clinical indicators of disease in a mouse model of colitis-associated colorectal cancer.

BACKGROUND: Emu Oil (EO) previously demonstrated therapeutic potential in a mouse model of colitis-associated CRC (CA-CRC). Saireito, a traditional Japanese medicine, has not been investigated in CA-CRC. AIM: To determine whether EO and Saireito could be therapeutic in an azoxymethane (AOM)/dextran sulphate sodium (DSS) model of CA-CRC. METHODS: Female C57BL/6 mice were assigned to groups (n = 10/group); 1) saline control, 2) saline+Saireito, 3) saline+EO, 4) saline+EO/Saireito, 5) AOM/DSS control, 6) AOM/DSS+Saireito, 7) AOM/DSS+EO and 8) AOM/DSS+EO/Saireito. Mice were intraperitoneally injected with saline or AOM (7.4 mg/kg) on day 0 and underwent three DSS/water cycles (2%w/v DSS for 7 days, 14 days water). Mice were orally-gavaged with either water (80 µL), Saireito (80 µL), EO (80 µL) or EO/Saireito (160 µL; 80 µL EO + 80 µL Saireito) thrice weekly. Daily bodyweight and disease activity index (DAI) were recorded and colonoscopies performed on days 20, 41 and 62. Mice were euthanized on day 63. p < 0.05 was considered statistically significant. RESULTS: AOM/DSS induced significant bodyweight loss throughout the trial (max -36%), which was attenuated by Saireito (max +7%), EO (max +5%) and EO/Saireito (max +14%; p < 0.05). AOM/DSS increased DAI compared to saline controls (p < 0.05), which was reduced by Saireito, EO and EO/Saireito (p < 0.05). All treatments reduced colonoscopically-assessed colitis severity (days 20 and 41; p < 0.05). EO/Saireito further decreased colitis severity compared to Saireito and EO alone (day 20; p < 0.05). Finally, EO and EO/Saireito resulted in fewer colonic tumours compared to AOM/DSS controls (p < 0.05). CONCLUSION: Combined EO and Saireito reduced disease and tumour development in AOM/DSS mice, suggesting therapeutic potential in CA-CRC.

Breath 13CO2-evidence for a noninvasive biomarker to measure added refined sugar uptake.

Increased consumption of added sucrose and high-fructose corn syrup in the human diet has been associated with increasing incidence of obesity and metabolic disease. There are currently no reliable, objective biomarkers for added sugar intake that could be used in individuals or population settings. 13C is a stable isotope of carbon, and measurement of blood 13C content has been proposed as a marker of added sugar consumption. This study aimed to determine if breath 13CO2 could represent an alternative, noninvasive biomarker to monitor added sugar intake. We undertook retrospective analyses of eight preclinical and human 13C-breath studies to define baseline breath 13CO2 characteristics. All samples were analyzed using isotope ratio mass spectrometry, and breath 13CO2 was expressed as the delta value, δ expressed as parts per thousand (‰). All data are expressed as mean ± SEM, with statistical significance considered at P < 0.05. Breath δ13CO2 was significantly elevated in a cumulative manner in rats and mice that consumed a diet containing at least 15% sucrose. Mice fed an American rodent chow diet containing 50% sucrose and 15% corn starch had a significantly higher breath δ13CO2 compared with rodents consuming an Australian rodent chow diet. Furthermore, breath δ13CO2 was significantly increased in a dose-dependent manner in humans that ingested a bolus dose of sucrose. These findings suggest application for baseline breath δ13CO2 as a noninvasive biomarker for added sugar consumption, with broad application for longitudinal assessment of population sugar intake and obesity management strategies.NEW & NOTEWORTHY We have found that breath 13CO2 is increased in rats and mice consuming diets high in sucrose. We also found that human breath 13CO2 is increased in humans consuming increasing amounts of sucrose. Our collective findings suggest that breath 13CO2 represents a potential marker of added dietary sugar consumption.

Emu oil and grape seed extract reduce tumour burden and disease parameters in murine colitis-associated colorectal cancer.

Ulcerative colitis is an incurable condition whereby patients are at an increased risk of developing colorectal cancer (CRC). We aimed to investigate the combination of Emu oil (EO) and grape seed extract (GSE) in an azoxymethane (AOM)/dextran sulphate sodium (DSS) model of colitis-associated CRC (CA-CRC). C57BL/6 mice (n = 10/group) were injected i.p. with saline or AOM (7.4 mg/kg) and underwent three DSS/water cycles. Mice were orally-gavaged thrice weekly with water (80 µl), EO (80 µl), GSE (80 µl; 400 mg/kg) or combined EO/GSE (160 µl). Mice were euthanized on day 63. AOM/DSS induced significant bodyweight loss (max -21%) and increased disease activity index (DAI) (max +83%) throughout the trial (P < 0.05). EO (max -53%), GSE (max -51%) and EO/GSE (max -71%) reduced DAI scores in AOM/DSS mice in all DSS cycles (P < 0.05). EO/GSE-treatment in AOM/DSS mice resulted in further DAI reduction compared with EO (max -62%) and GSE (max -71%) alone (P < 0.05). AOM/DSS mice presented with severe colonoscopically-assessed colitis at all time-points, which was reduced by EO, GSE and EO/GSE (P < 0.05). EO, GSE and EO/GSE reduced the number of colonic tumours compared with AOM/DSS controls (P < 0.05). Myeloperoxidase (acute inflammation) and fluorescein isothiocyanate-dextran levels (intestinal permeability) were increased in AOM/DSS controls (P < 0.05). EO (-58%) and EO/GSE (-77%) reduced fluorescein isothiocyanate-dextran compared with AOM/DSS controls (P < 0.05), with no effect on myeloperoxidase. Histologically-assessed severity scores were increased in the distal colon of AOM/DSS mice compared with saline (P < 0.05), with no effect observed following treatment. The combination of EO and GSE improved clinical indicators and reduced colonic tumours in AOM/DSS treated mice, suggesting potential in CA-CRC management.

Orally administered emu oil attenuates disease in a mouse model of Crohn's-like colitis.

Crohn's disease is a severe, incurable inflammatory bowel disease. Orally administered emu oil has demonstrated anti-inflammatory properties in previous models of gastrointestinal disease. We aimed to determine whether orally administered emu oil could attenuate disease in a mouse model of Crohn's-like colitis. Female ARC(s) mice (CD-1 equivalent, n = 10/group) were intra-rectally administered water (120 µL) or trinitrobenzene sulfonic acid (TNBS; 3 mg in 50% ethanol; 120 µL bolus) on day 0. Mice were orally administered water (80 µL) or emu oil (80 µL or 160 µL) daily for five days and euthanized on day six. Bodyweight and disease activity were recorded daily. Colonoscopy, burrowing activity, facial grimace, histological parameters (damage severity, small intestinal villus height/crypt depth and colonic crypt depth), myeloperoxidase activity and intestinal permeability were assessed. P < 0.05 was considered statistically significant. TNBS decreased bodyweight (days 1, 2, 4; P < 0.05) and increased disease activity (days 1-6; P < 0.01), compared to normal controls. Emu oil (80 µL) attenuated disease activity on days 5-6 (P < 0.05), although bodyweight loss was not significantly impacted (P > 0.05). Facial grimace and colonoscopy scores were significantly increased in TNBS-control mice; effects attenuated by both volumes of emu oil (P < 0.001). TNBS increased histological damage severity compared to normal controls (P < 0.05); an effect attenuated by 80 µL emu oil (proximal and distal colon; P < 0.05) and 160 µL emu oil (distal colon; P < 0.01). In the ileum, villus height and crypt depth were unaffected by TNBS or emu oil treatment compared to normal (P > 0.05). TNBS-induced distal colonic crypt lengthening was unaffected following emu oil administration (P > 0.05). Remaining parameters, including burrowing, myeloperoxidase activity and intestinal permeability, were unchanged across all treatment groups (P > 0.05). In normal mice, emu oil treatment did not significantly impact any parameter compared to normal controls. In conclusion, emu oil reduced overall disease severity and facial grimace scores in TNBS mice. These results suggest therapeutic potential for orally administered emu oil in the management of Crohn's disease.

Excreta biomarkers in response to different gut barrier dysfunction models and probiotic supplementation in broiler chickens.

Increased intestinal permeability (IP) and inflammation are both linked with functionality of the intestinal barrier and in particular enterocytes. Currently, almost all assessment methods of the intestinal barrier function are invasive. The present study aimed to quantify selected proteins as novel biomarkers in excreta of broiler chickens to facilitate non-invasive assessment of gut barrier function using enzyme-linked immunosorbent assays (ELISA). It was further hypothesised that probiotics as feed additives may counteract gut barrier dysfunction. A 3 × 2 factorial arrangement of treatments was used with the main factors being gut barrier dysfunction models (control, rye-based diet, and dexamethasone-DEX) with and without probiotic supplementation (a three-strain Bacillus) using 72 male Ross 308 day-old chickens. Each of the 6 experimental treatments was replicated 12 times. On d 21 of age, fluorescein isothiocyanate dextran (FITC-d) uptake into serum was examined to test IP. Fresh excreta samples were collected on d 20. The biomarkers included alpha-1 antitrypsin (A1AT), intestinal fatty acid binding protein (I-FABP), lipocalin-2 (LCN2), fibronectin (FN), intestinal alkaline phosphatase (IAP), ovotransferrin (OVT) and superoxide dismutase [Cu-Zn] (SOD1). Only DEX increased (P<0.001) FITC-d passage to the blood on d 21 of age, indicating a greater IP. The excreta concentrations of A1AT, I-FABP and SOD1 were unaltered by the experimental treatments. DEX increased (P<0.05) FN concentration in excreta compared with control birds. Conversely, inclusion of rye in the diet reduced (P<0.05) FN but increased (P<0.001) OVT in excreta. Independently, DEX decreased IAP (P<0.05) in excreta compared with control and rye-fed birds. The excreta concentration of LCN2 tended (P = 0.086) to increase in birds injected by DEX. There was no demonstrable effect of probiotic addition on any of the studied parameters. Among the tested biomarkers, FN, IAP, and LCN2 revealed promise as biomarkers of intestinal barrier function quantified by ELISA kits.

Intestinal stem cells promote crypt fission during postnatal growth of the small intestine.

OBJECTIVE: Wnt-ß-catenin signalling is essential for intestinal stem cells. Our aim was to investigate the relationship between intestinal stem cells and crypt fission which peaks during infancy. DESIGN: Duodenal biopsies were obtained during endoscopy to assess the severity of reflux oesophagitis of 15 infants, children and teenagers, which would not affect the duodenum. Samples of small intestine were also obtained from rats 7-72 days of life. Crypt fission was assessed using microdissection of 100 whole crypts and recording the percentage of bifid crypts. Intestinal LGR5+ stem cells were identified by in situ hybridisation. Rats were treated with Dickkopf to block Wnt-ß-catenin signalling. RESULTS: Crypt fission peaked during infancy before declining after 3-4 years in humans and after 21 days of life in rats. Occasional mitotic figures were seen in bifid crypts during early fission. Stem cells were elevated for a greater period during infancy and childhood in humans. Clustering of Paneth cells was present around the stem cells at the crypt base. Dickkopf reduced the number of stem cells and crypt fission to 45% and 29%, respectively, of control values, showing dependence of both crypt fission and Lgr5+ stem cells on Wnt signalling. However, Dickkopf did not decrease mitotic count per crypt, indicating a difference in signalling between stem cells and their progeny in the transit amplifying zone. CONCLUSION: Crypt fission peaks during infancy and is dependent on intestinal stem cells. This is relatively hidden by 'a cloak of invisibility' due to the low proliferation of stem cells.

Affective state determination in a mouse model of colitis-associated colorectal cancer.

Behavioural indicators of affective state, including burrowing, clinical scores and the Mouse Grimace Score have not yet been validated in mouse models of chronic gastrointestinal disease. Additionally, a comparison of these methods has not been characterised. This study aimed to determine which behavioural assessment was the optimal indicator of disease, evidenced by correlation with clinically-assessed measures, in an azoxymethane (AOM)/dextran sulphate sodium (DSS) mouse model of colitis-associated colorectal cancer. C57BL/6 mice were allocated to four groups (n = 10/group); 1) saline control, 2) saline+buprenorphine, 3) AOM+DSS+water, 4) AOM+DSS+buprenorphine. Mice were gavaged thrice weekly with water or buprenorphine (0.5mg/kg; 80µL) for 9 weeks. Disease activity index (DAI) was measured daily; burrowing and grimace analyses occurred on days -1, 5, 19, 26, 40, 47 and 61. Colonoscopies were performed on days 20, 41 and 62. All animals were euthanized on day 63. Burrowing activity and retrospective grimace analyses were unaffected (P>0.05), whilst DAI was significantly increased (P<0.05) in mice with colitis-associated colorectal cancer compared to normal controls. In addition, DAI was positively correlated with colonoscopically-assessed severity and tumour number (P<0.05). We conclude that traditional measures of DAI or clinical scoring provide the most reliable assessment of wellbeing in mice with colitis-associated colorectal cancer.

Chemotherapy-induced mucositis development in a murine model of colitis-associated colorectal cancer.

Objectives: Ulcerative colitis is an incurable inflammatory bowel disease that increases the risk of colorectal cancer (CRC). 5-Fluorouracil (5-FU) is the predominant chemotherapy for CRC patients; however, undesirable side-effects, including mucositis, are common. This study utilised 5-FU-treatment in a model of colitis-associated CRC to develop a pre-clinical setting of intestinal mucositis coincident with manifestation of CRC.Materials/methods: On day 0, female C57BL/6 mice (n = 10/group); (1) saline control, (2) AOM/DSS control, or (3) AOM/DSS + 5-FU were injected with saline or AOM (i.p; 7.4 mg/kg). Groups 2 and 3 underwent cycles of seven days 2%w/v DSS followed by 14 days plain water. After three cycles, 5-FU was administered weekly (i.p; 75 mg/kg) to group 3 for five weeks. Clinical indicators were measured daily and colonoscopy performed at four time-points. Mice were euthanized at 13 weeks (day 91). Intestinal sections were collected for histological and biochemical analyses. p < .05 was considered significant.Results: AOM/DSS resulted in bodyweight loss, increased disease activity index, colitis-severity and tumour number compared to saline controls (p < .05). 5-FU-treatment in AOM/DSS mice decreased bodyweight and disease activity index at selected time-points compared to AOM/DSS controls (p < .05). 5-FU did not impact colitis-severity or overall tumour burden; although, resulted in fewer small tumours compared to AOM/DSS controls (<2mm; p < .05). AOM/DSS increased histological severity scores in intestinal sections (p < .05), however, 5-FU-treatment did not further increase histologically-assessed disease severity (p > .05).Conclusion: Weekly 5-FU administration at a dose of 75 mg/kg was insufficient to reduce overall tumour burden or induce intestinal mucositis in the AOM/DSS mouse model.

Use of the Rat Grimace Scale to Evaluate Visceral Pain in a Model of Chemotherapy-Induced Mucositis.

The rat grimace scale (RGS) is a measure of spontaneous pain that evaluates pain response. The ability to characterize pain through a non-invasive method has considerable utility for numerous animal models of disease, including mucositis, a painful, self-limiting side-effect of chemotherapy treatment. Preclinical studies investigating novel therapeutics for mucositis often focus on pathological outcomes and disease severity. These investigations fail to measure pain, in spite of reduction of pain being a key clinical therapeutic goal. This study assessed the utility of the RGS for pain assessment in a rat model of mucositis, and whether changes in disease activity index (DAI) and open field test (OFT) reflected the grimace responses recorded. Sixty tumor-bearing female Dark Agouti rats were injected with either saline or 5-Fluourouracil alone, or with co-administration of opioid analgesics. Whilst differences in DAI were observed between treatment groups, no difference in RGS scores or OFT were demonstrated. Significant increases in grimace scores were observed across time. However, whilst a statistically significant change may have been noted, the biological relevance is questionable in terms of practical usage, since an observer is only able to score whole numbers. Development of effective pain assessment methods in animal models is required to improve welfare, satisfy regulatory requirements, and increase translational validity of the model to human patients.

Prebiotics Fructo-, Galacto-, and Mannan-Oligosaccharide Do Not Protect against 5-Fluorouracil-Induced Intestinal Mucositis in Rats.

BACKGROUND: Prebiotics selectively stimulate the growth of beneficial bacteria within the gastrointestinal tract, and have been investigated in human and animal studies for their capacity to improve intestinal health. OBJECTIVE: We investigated the prebiotics fructo-oligosaccharide (FOS), galacto-oligosaccharide (GOS), and mannan-oligosaccharide (MOS) for their potential to alleviate intestinal damage in rats. METHODS: Female Dark Agouti rats (6-8 wk old, 110-150 g) were allocated to 1 of the following treatment groups (n = 8/group): saline/water, saline/FOS, saline/GOS, saline/MOS, 5-fluorouracil (5FU)/water, 5FU/FOS, 5FU/GOS, and 5FU/MOS. Rats were pretreated with either 5% GOS, MOS, or FOS or vehicle (water) from day -12 to day 0. On day 0, rats received a single intraperitoneal injection of saline or 5FU. Metabolic data were recorded daily and all rats were killed on day 3. Histopathology was quantified in hematoxylin and eosin-stained sections. Intestinal sucrase and myeloperoxidase activity were quantified by biochemical assay. Fecal SCFAs-acetic, propionic, and butyric acid-were also measured. Statistical analysis was by repeated-measures, 2-factor ANOVA or Kruskal-Wallis and Mann-Whitney U test; P < 0.05 was considered statistically significant. RESULTS: Body weight was significantly decreased in all treatment groups after 5FU injection, with no change in body weight observed in any prebiotic treatment group. Total food intake was lower by ≥7% in the GOS treatment group pre-5FU than in all other groups (P < 0.05). Ileal villus height was 18% higher in GOS-treated rats pre-5FU than in respective water controls (P < 0.05). Jejunal and ileal villus height and crypt depth were significantly decreased in all treatment groups after 5FU injection, with no prebiotic effect observed. SCFAs were differentially increased in prebiotic treatment groups compared with water-only controls (P < 0.05). CONCLUSIONS: FOS, GOS, and MOS have differential effects in modifying small intestinal pathology and SCFA profiles in rats with healthy and damaged small intestinal mucosa.

Combined Nutraceuticals: A Novel Approach to Colitis-Associated Colorectal Cancer?

Ulcerative colitis is an unremitting and lifelong inflammatory bowel disease that is increasing in prevalence worldwide. Patients display various clinical symptoms such as abdominal pain, diarrhea and fatigue. The etiology of ulcerative colitis remains unknown and the current pharmaceutical treatments are variably effective and not curative, highlighting the need for improved therapeutic approaches. Furthermore, patients with ulcerative colitis are at an increased risk of developing colorectal cancer. Some naturally sourced agents, named nutraceuticals, have been identified to possess anti-inflammatory and antioxidant properties. Of particular interest is Emu Oil, grape seed extract and Japanese Kampo medicine. Previously, Emu Oil has protected and repaired intestinal damage in models of gastrointestinal diseases including colitis and colitis-associated colorectal cancer. Additionally, grape seed extract possesses anticancer properties in vitro. Moreover, Kampo medicine, composed of herbal ingredients, is widely used in Japan for the treatment of various medical conditions and has demonstrated efficacy in targeting cancer cells in vitro. Nutraceuticals in combination have not yet been widely investigated in a setting of colitis-associated colorectal cancer. Investigation into the efficacy of Emu Oil combined with other nutraceuticals, including grape seed extract and Kampo medicine, is warranted as they may provide a novel approach to conventional colitis and colorectal cancer management.

Emu Oil reduces disease severity in a mouse model of chronic ulcerative colitis.

Objective: Ulcerative colitis (UC) is characterized by mucosal inflammation and ulceration of the large intestine. Emu Oil (EO) has been reported to protect the intestine against mucositis, NSAID-enteropathy, UC-associated colorectal cancer and acute UC. We aimed to determine whether EO could reduce the severity chronic UC in mice. Methods: Female C57BL/6 mice (n = 10/group) were orally administered (gavage) water (Groups 1-2) or EO (Groups 3: low dose-80 µl and 4: high dose-160 µl), thrice weekly. Group 1 mice consumed plain drinking water throughout the trial. Groups 2-4 mice underwent two cycles [each consisting of seven days dextran sulfate sodium (DSS; 2% w/v) and 14 days water], followed by a third DSS week. All mice were euthanized two days later (day 51). Bodyweight, disease activity index (DAI), burrowing activity, myeloperoxidase activity, crypt depth and histologically assessed damage severity were assessed. p < .05 was considered significant. Results: DSS decreased bodyweight and increased DAI compared to normal controls (p < .05), which was partially attenuated by both EO doses (p < .05). Burrowing activity was impaired in DSS-controls compared to normal controls (days 27 and 40); an effect prevented by both EO doses (p < .05). DSS increased colonic myeloperoxidase activity and crypt depth compared to controls (p < .05), with no significant EO effect. Moreover, DSS increased colonic damage severity compared to normal controls (p < .001). Importantly, both EO doses decreased distal colonic damage severity compared to DSS-controls (p < .001). Conclusions: Emu Oil attenuated clinically- and histologically-assessed disease severity in a mouse model of chronic UC. Emu Oil demonstrates promise as an adjunct to conventional treatment options for UC management.

Active ß-Catenin Signaling in the Small Intestine of Humans During Infancy.

BACKGROUND: Wnt-ß-catenin signaling is essential for homeostasis of intestinal stem cells in mice and is thought to promote intestinal crypt fission. AIMS: The aim of this study was to investigate Wnt-ß-catenin signaling in intestinal crypts of human infants. METHODS: Duodenal biopsies from nine infants (mean, range 0.9 years, 0.3-2 years) and 11 adults (mean, range 43 years, 34-71 years) were collected endoscopically. Active ß-catenin signaling was assessed by cytoplasmic and nuclear ß-catenin, nuclear c-Myc, and cytoplasmic Axin-2 expression in the base of crypts. Tissues were stained by an immunoperoxidase staining technique and quantified as pixel energy using cumulative signal analysis. Data were expressed as mean ± SD and significance assessed by Student's t test. RESULTS: Crypt fission was significantly higher in infants compared to adults (16 ± 8.6% versus 0.7 ± 0.6%, respectively, p < 0.0001). Expression of cytoplasmic and nuclear ß-catenin was 1.8-fold (p < 0.0001) and 2.9-fold (p < 0.0001) higher in infants, respectively, while cytoplasmic Axin-2 was 3.1-fold (p < 0.0001) increased in infants. c-Myc expression was not significantly different between infants and adults. Expression was absent in Paneth cells but present in the transit amplifying zone of crypts. Crypt base columnar cells, which were intercalated between Paneth cells, expressed c-Myc. CONCLUSIONS: Wnt-ß-catenin signaling was active in crypt base columnar cells (i.e., intestinal stem cells) in human infants. This signaling could promote crypt fission during infancy. Wnt-ß-catenin signaling likely acts in concert with other pathways to promote postnatal growth.