Protective Effects of Oliveria decumbens Hydroalcoholic Extract in an Acetic Acid-Induced Ulcerative Colitis Rat Model

Background and objectives: Ulcerative colitis is a chronic inflammatory bowel disease characterized by mucosal and submucosal damage in the colon. This study evaluated the protective effect of Oliveria decumbens Vent. (locally known as “Moshkoorak”), a plant used in the folk medicine of southwest Iran for treating infectious and digestive disorders, as well as acetic acid-induced ulcerative colitis in rats. Methods: Ulcerative colitis was induced in male Wistar rats via intrarectal administration of acetic acid. The rats were pretreated with a hydroalcoholic extract of O. decumbens (100, 250, or 500 mg/kg) for 7 days before the induction of ulcerative colitis and 3 days after its induction. Colon biopsies were analyzed for the extent of tissue damage, histopathological changes, and the ulcer index. Results: Treatment with 500 mg/kg of O. decumbens extract significantly reduced ulcer severity, lesion area, and scores for macroscopic/histological damage compared to the control group. The 100 mg/kg dose also showed moderate (but non-dose-dependent) improvements in tissue pathology without toxicity. Conclusion: The anti-colitis effects of O. decumbens may arise from the systemic absorption of bioactive compounds and/or the local actions of non-absorbable constituents in the colon. These findings support further preclinical and clinical investigations of its potential as a complementary therapy for ulcerative colitis.