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

Abstract Background. 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. Objective. We aimed to determine whether ZMG, alone or in combination with Emu Oil, could reduce acute colitis severity in rats. Methods. 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 activity were assessed. p<0.05 was considered significant. Results. DSS increased disease severity (days 3-6) compared to normal controls (p<0.05). Importantly, in DSS-administered rats, ZMG reduced disease activity index (day 6) compared to controls and EO-treated rats (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 DMCs compared to normal controls (p<0.001); an effect decreased only by EO (p<0.05). Colonic myeloperoxidase activity increased following DSS consumption (p<0.05); notably, ZMG, EO and ZMG/EO treatments decreased myeloperoxidase activity compared to DSS controls (p<0.001). EO, ZMG and ZMG/EO did not impact any parameter in normal animals. Conclusions. Emu Oil and ZMG independently decreased selected indicators of colitic disease severity in rats; however, the combination did not reveal any additional benefit.