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

Abstract

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. Impact statement The submitted work details novel research to contribute to the field of inflammatory bowel diseases, specifically Crohn’s disease and alternative therapies. This work is important as current therapies for Crohn’s disease are variably effective and often significantly compromise patient quality of life. Emu oil, used in the current study, has the potential to alleviate disease severity and promote intestinal repair in a mouse model of Crohn’s-like colitis. The new findings from this manuscript, whereby emu oil attenuated disease severity from clinical scores and colonoscopy results, add to the literature of inflammatory bowel disease mouse models and support the therapeutic potential of emu oil. This research may advance the progression to clinical trials and ultimately the commercialization of emu oil as an adjunctive or alternative therapy for the detrimental inflammatory bowel diseases.

Methods Used and Application of the Mouse Grimace Scale in Biomedical Research 10 Years on: A Scoping Review

“…In 10 studies, summation of the individual action units scores was performed to arrive at the final score (maximum score of 10 for five FAUs). The method of achieving the final score was unclear in the remaining two studies [ 28 , 58 ]. A number of studies accounted for individual responses to pain by using mean difference scores in data presentation and analysis to correct for baseline grimace scores.…”

“…In the majority of cases (31 studies), data from these tests corroborated MGS scoring. In the remaining studies, either no association was seen with the chosen measures [ 26 , 53 , 58 , 72 ], or there was unclear reporting or a lack of direct comparison in the same animals [ 39 , 45 ].…”

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Emu Oil and Zinc Monoglycerolate Influence the Course of Disease in a Rat Model of Ulcerative Colitis

“…Emu Oil contains a lipid content of 98.0% (Abimosleh et al 2012b) and variable levels of compounds with antioxidant properties (Chartier et al 2019;Mashtoub 2017). Previously, we demonstrated the anti-inflammatory and reparative properties of orally-administered Emu Oil in animal models of acute (Abimosleh et al 2012a) and chronic colitis (Safaeian et al 2019), colitis-associated colorectal cancer (Chartier et al 2021a;Chartier et al 2018;Chartier et al 2021b;Mashtoub et al 2022), acute Crohn's-like colitis (Mitchell et al 2020), nonsteroidal anti-inflammatory drug-induced enteropathy (Abimosleh et al 2013) and chemotherapy-induced intestinal mucositis (Mashtoub et al 2016;Mashtoub et al 2013;Raghu Nadhanan et al 2012).…”