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 mu L) or trinitrobenzene sulfonic acid (TNBS; 3 mg in 50% ethanol; 120 mu L bolus) on day 0. Mice were orally administered water (80 mu L) or emu oil (80 mu L or 160 mu L) 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 mu L) 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 mu L emu oil (proximal and distal colon;P < 0.05) and 160 mu L 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.