en Gastrointestinal Physiology/Pharmacology Gastrointestinal Physiology/Pharmacology Experimental research article Experimental research article <div style="text-align: justify;"><strong>Introduction: </strong>This study was designed to evaluate the effects of cinnamon extract on ulcerative colitis in rats.<strong> Methods:</strong> Thirty-two male Wistar rats were divided into four groups: untreated control, positive control group (acetic acid-induced ulcerative colitis), cinnamon extract treated group (150mg/kg/day) and treated group with prednisolone (4mg/kg/day). After 10 consecutive days, the rats were euthanized and examined for the production of inflammatory mediators and oxidative stress indices in the intestinal tissue. <strong>Results:</strong> Data showed that both therapies could reduce the cumulative disease score. The results also indicated that treatment with cinnamon caused a more benefit in restoring the total antioxidant capacity of the colonic specimens of the colitis-induced rats compared to treatment with prednisolone. The levels of myeloperoxidase and nitric oxide were down-regulated in the colons of cinnamon treated rats more than prednisolone groups. Prednisolone significantly decreased the levels of TNF-&alpha; and IL-6 cytokines more than colitis rats treated with cinnamon extract. The levels of COX-2 were decreased and conversely, the total protein content of colonic homogenates was increased in the colons of both treatment groups in a non-significant manner, compared to untreated colitis rats. <strong>Conclusion:</strong> These results demonstrated cinnamon as herbal medicine is a promising strategy to improve the inflammation in a rat model of ulcerative colitis. It is logical to consider some of the beneficial effects of cinnamon extract associated with its direct antioxidant benefits, along with its direct anti-inflammatory benefits.</div> Ulcerative colitis, Cinnamon extract, Inflammation 140 149 http://ppj.phypha.ir/browse.php?a_code=A-10-1177-1&slc_lang=en&sid=1 Mojtaba Salamatian mojtaba.salamatian@gmail.com 3200319475328460029586 3200319475328460029586 No Department of Internal Medicine and Clinical Pathology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Vahid Mohammadi v.mohammadi@urmia.ac.ir 3200319475328460029587 3200319475328460029587 Yes Department of Internal Medicine and Clinical Pathology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Seyyed Meysam Abtahi Froushani sm.abtahi@urmia.ac.ir 3200319475328460029588 3200319475328460029588 No Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran