Emu Oil Improves Clinical Indicators of Disease in a Mouse Model of Colitis-Associated Colorectal Cancer

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.

Neurocognitive testing in a murine model of mucopolysaccharidosis type IIIA

Mucopolysaccharidosis type IIIA (MPS IIIA) is an inherited metabolic disorder caused by a lysosomal enzyme deficiency resulting in heparan sulphate (HS) accumulation and manifests with a progressive neurodegenerative phenotype. A naturally occurring MPS IIIA mouse model is invaluable for preclinical evaluation of potential treatments but the ability to effectively assess neurological function has proved challenging. Here, the aim was to evaluate a set of behaviour tests for their reliability in assessing disease progression in the MPS IIIA mouse model. Compared to wild-type (WT) mice, MPS IIIA mice displayed memory and learning deficits in the water crossmaze from mid-stage disease and locomotor impairment in the hind-limb gait assessment at late-stage disease, supporting previous findings. Declined wellbeing was also observed in the MPS IIIA mice via burrowing and nest building evaluation at late-stage disease compared to WT mice, mirroring the progressive nature of neurological disease. Excessive HS accumulation observed in the MPS IIIA mouse brain from 1 month of age did not appear to manifest as abnormal behaviours until at least 6 months of age suggesting there may be a threshold of HS accumulation before measurable neurocognitive decline. Results obtained from the open field and three-chamber sociability test are inconsistent with previous studies and do not reflect MPS IIIA patient disease progression, suggesting these assessments are not reliable. In conclusion, water cross-maze, hind-limb gait, nest building and burrowing, are promising assessments in the MPS IIIA mouse model, which produce consistent results that mimic the human disease.

Ecological and dynamic analysis of gut microbiota in the early stage of azomethane-dextran sodium sulfate model in mice

The success rate of azomethane-dextran sodium sulfate (AOM-DSS) model in mice has been a long-standing problem. Treatment of AOM and the first round DSS induces acute colitis and is of great significance for the success of AOM-DSS model. In this study, we focused on the role of gut microbiota in the early stage of AOM-DSS model. Few mice with obvious weight loss and high disease-activity score survived from double strike of AOM and the first round DSS. Different ecological dynamics of gut microbiota were observed in AOM-DSS treated mice. Pseudescherichia, Turicibacter, and Clostridium_XVIII were of significance in the model, uncontrolled proliferation of which accompanied with rapid deterioration and death of mice. Akkermansia and Ruthenibacterium were significantly enriched in the alive AOM-DSS treated mice. Decrease of Ligilactobacillus, Lactobacillus, and Limosilactobacillus were observed in AOM-DSS model, but significant drop of these genera could be lethal. Millionella was the only hub genus of gut microbiota network in dead mice, which indicated dysbiosis of the intestinal flora and fragility of microbial network. Our results will provide a better understanding for the role of gut microbiota in the early stage of AOM-DSS model and help improve the success rate of model construction.

Diagnostic Ability of Methods Depicting Distress of Tumor-Bearing Mice

Simple Summary

Experiments on animals can provide important information for improving the life expectancy and life quality of patients. At the same time, the welfare of these animals is a growing public concern. Therefore, many laws and international guidelines were established with the goal of minimizing the harm inflicted on these animals. A prerequisite of improving animal welfare is to correctly measure how much distress the experiments cause to these animals. However, it is often unknown as to which methods are appropriate to assess distress. Mice bearing subcutaneous tumors are the most frequently used animal model to study the therapeutic effects of drugs. We evaluated if body weight, faecal corticosterone metabolites concentration, burrowing activity and a distress score were capable of differentiating between mice before cancer cell injection and mice bearing large tumors. We observed that only adjusted body weight change and faecal corticosterone metabolites concentration were capable of measuring distress caused by large subcutaneous tumors. Therefore, these two methods are appropriate to assess the welfare of mice with subcutaneous tumors. This knowledge provides a solid basis to optimize animal welfare in future studies. For example, both methods can define the ideal time point when an experiment should end by finding a good compromise between minimal distress for the animals and maximal knowledge gain for mankind.

Abstract

Subcutaneous tumor models in mice are the most commonly used experimental animal models in cancer research. To improve animal welfare and the quality of scientific studies, the distress of experimental animals needs to be minimized. For this purpose, one must assess the diagnostic ability of readout parameters to evaluate distress. In this study, we evaluated different noninvasive readout parameters such as body weight change, adjusted body weight change, faecal corticosterone metabolites concentration, burrowing activity and a distress score by utilising receiver operating characteristic curves. Eighteen immunocompromised NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ mice were used for this study; half were subcutaneously injected with A-375 cells (human malignant melanoma cells) that resulted in large tumors. The remaining mice were inoculated with SCL-2 cells (cutaneous squamous cell carcinoma cells), which resulted in small tumors. The adjusted body weight and faecal corticosterone metabolites concentration had a high diagnostic ability in distinguishing between mice before cancer cell injection and mice bearing large tumors. All other readout parameters had a low diagnostic ability. These results suggest that adjusted body weight and faecal corticosterone metabolites are useful to depict the distress of mice bearing large subcutaneous tumors.

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.

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.

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.

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.

Curcumin Administered as Micellar Solution Suppresses Intestinal Inflammation and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common cancers and preventive strategies based on natural compounds are highly desirable. Curcumin, the principal bioactive compound in Curcuma longa, was described to have multiple beneficial health effects. A drawback, however, is the low bioavailability due to its insolubility in water. Here, we studied whether nanoscaled micellar curcumin with improved bioavailability administered in drinking water reduces inflammation and CRC formation in a mouse model. C57BL6 wild-type (WT) mice and a strain defective in the DNA repair enzyme O⁶-methylguanine-DNA methyltransferase (MGMT) were used, in which tumors were induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS). Inflammation and tumor formation were determined by mini-colonoscopy. Micellar curcumin (mCur) administered in drinking water significantly reduced AOM/DSS-induced colorectal inflammation in both WT and MGMT-deficient mice as compared to animals receiving drinking water with micelles not containing curcumin. In line with this, the tumor yield and tumor score were significantly lower in mCur-treated mice compared to the control group. No adverse effects were observed in animals receiving mCur daily for at least three months. Overall, our data show that chronic oral administered micellar curcumin is well tolerated and reduces chemical-induced gut inflammation and CRC formation in mice.Impact: The study shows that micellar curcumin with high bioavailability chronically administered at low and physiologically relevant concentration suppresses inflammation and carcinogenesis in a mouse colorectal tumor model.

Animal models of mucositis: critical tools for advancing pathobiological understanding and identifying therapeutic targets

PURPOSE OF REVIEW

Mucositis remains a prevalent, yet poorly managed side effect of anticancer therapies. Mucositis affecting both the oral cavity and gastrointestinal tract predispose to infection and require extensive supportive management, contributing to the growing economic burden associated with cancer care. Animal models remain a critical aspect of mucositis research, providing novel insights into its pathogenesis and revealing therapeutic targets. The current review aims to provide a comprehensive overview of the current animal models used in mucositis research.

RECENT FINDINGS

A wide variety of animal models of mucositis exist highlighting the highly heterogenous landscape of supportive oncology and the unique cytotoxic mechanisms of different anticancer agents. Golden Syrian hamsters remain the gold-standard species for investigation of oral mucositis induced by single dose and fractionated radiation as well as chemoradiation. There is no universally accepted gold-standard model for the study of gastrointestinal mucositis, with rats, mice, pigs and dogs all offering unique perspectives on its pathobiology.

SUMMARY

Animal models are a critical aspect of mucositis research, providing unprecedent insight into the pathobiology of mucositis. Introduction of tumour-bearing models, cyclic dosing scheduled, concomitant agents and genetically modified animals have been integral in refining our understanding of mucositis.

Development and characterization of ten novel microsatellite loci for the emu (Dromaius novaehollandiae) and genetic diversity of Japanese farm populations

The emu (Dromaius novaehollandiae) is a useful poultry animal farmed for fat, meat, and eggs. Genetic structure and relationships among farmed emu populations in Japan are unknown and the number of microsatellite markers for genetic analysis of the emu is insufficient. In this study, we isolated 16 microsatellites from the emu genome and developed ten new microsatellite markers. These microsatellite markers were used to characterize three farm emu populations in Japan. The number of alleles ranged from 3 to 13 and the expected (H_E) and observed heterozygosity (H_O) of these microsatellite loci was 0.187-0.802 and 0.179-0.647, respectively. The polymorphic information content ranged from 0.176 to 0.786. Positive inbreeding coefficient (F_IS) values were detected in all tested populations, and they ranged from 0.027 to 0.540. These results suggest that farm populations of the emu in Japan resulted from inbreeding. The fixation index (F_ST) values ranged from 0.026 to 0.061, and phylogenetic trees and population structure analysis confirmed no definitive genetic differentiation among the three populations. Therefore, these populations are at a relatively low level of genetic differentiation at present. The microsatellite markers developed in our study can be utilized for genetic analysis and preservation of genetic resources in the emu.

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.

Flightless I exacerbation of inflammatory responses contributes to increased colonic damage in a mouse model of dextran sulphate sodium-induced ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by cytokine driven inflammation that disrupts the mucosa and impedes intestinal structure and functions. Flightless I (Flii) is an immuno-modulatory protein is a member of the gelsolin family of actin-remodelling proteins that regulates cellular and inflammatory processes critical in tissue repair. Here we investigated its involvement in UC and show that Flii is significantly elevated in colonic tissues of patients with inflammatory bowel disease. Using an acute murine model of colitis, we characterised the contribution of Flii to UC using mice with low (Flii+/-), normal (Flii+/+) and high Flii (FliiTg/Tg). High levels of Flii resulted in significantly elevated disease severity index scores, increased rectal bleeding and degree of colon shortening whereas, low Flii expression decreased disease severity, reduced tissue inflammation and improved clinical indicators of UC. Mice with high levels of Flii had significantly increased histological disease severity and elevated mucosal damage with significantly increased inflammatory cell infiltrate and significantly higher levels of TNF-α, IFN-γ, IL-5 and IL-13 pro-inflammatory cytokines. Additionally, Flii overexpression resulted in decreased β-catenin levels, inhibited Wnt/β-catenin signalling and impaired regeneration of colonic crypts. These studies suggest that high levels of Flii, as is observed in patients with UC, may adversely affect mucosal healing via mechanisms involving Th1 and Th2 mediated tissue inflammation and Wnt/β-catenin signalling pathway.

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.

Intestinal homeostasis is restored in mice following a period of intestinal growth induced by orally administered Emu Oil

Previously, we reported that orally administered Emu Oil (EO) increases mucosal thickness in the small intestine and colon in rodent models of chemotherapy-induced mucositis and colitis. However, it remains unclear whether mucosal thickening (crypt and villus lengthening) represents a process of normal or aberrant growth. We sought to determine if villus height (VH) and crypt depth (CD) measurements returned to normal in EO-treated rats following withdrawal of EO therapy. Dark agouti rats ( n = 8/group) were gavaged daily for 10 days with water, olive oil (OO), or EO (0.5 mL or 1 mL). Groups of rats were euthanized on days 10 and 17. Intestinal weights, lengths, VH, and CD were quantified. P < 0.05 was considered significant. On day 10, jejuno-ileum weight was increased by OO (26%) and EO (0.5 mL: 15%; 1 mL: 29%) compared to water controls ( P < 0.01), which was normalized by day 17. On days 10 and 17, jejuno-ileum length was greater in OO- (12%) and EO-treated rats (0.5 mL: 8%; 1 mL: 12%; P < 0.05), relative to water controls. On day 10, OO and EO increased ileal VH (OO: 32%; 0.5 EO: 22%; EO: 35%; P < 0.01) and CD (OO: 17%; 0.5 EO: 13%; EO: 22%) compared to water controls. Importantly, however, after withdrawal of all oils, VH and CD measurements returned to normal control values. Moreover, the VH:CD ratio (potential indicator of dysplasia) remained unchanged in all experimental groups on days 10 and 17. The restoration of normal intestinal architecture following cessation of Emu Oil therapy supports its safety for application in intestinal disorders. Impact statement Uncontrolled inflammation and intestinal proliferation can predispose to the development of colorectal cancer. In previous pre-clinical studies, we demonstrated that oral administration of Emu Oil promotes intestinal repair via stimulation of the mucosa in response to tissue injury and inflammation. Therefore, it was important to determine if Emu Oil administration did not promote the precocious development of colorectal cancer. The current study revealed that Emu Oil returned indicators of intestinal proliferation back to normal values after a period of seven days. These data strongly support the safety of Emu Oil for further studies in the context of bowel inflammation.