en Biomarkers (diagnosis & treatment) Biomarkers (diagnosis & treatment) Original Article Original Article <p>Oleuropein is one of the main phenolic secoiridoid of the olive leaf extract, which is known for its antioxidant and anti-inflammatory effects. The main objective of the present study was to investigate the effectiveness of oleuropein in the ulcerative colitis treatment. <a name="_gjdgxs"></a>An experimental study was designed on rats, which were divided into three groups, group 1 (normal control), group 2 (induced for ulcerative colitis and untreated), and group 3 (induced for ulcerative colitis and treated with oleuropein). Colonic tissue samples were collected from all studied groups and the oxidative stress and antioxidant activity were assessed by evaluating malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), myeloperoxidase (MPO), and nitric oxide (NO) levels. The expression levels of pro-inflammatory cytokines such as <em>IL-1&beta;</em>, <em>TNF-&alpha;</em>, <em>IL-10</em>, <em>COX-2</em>, <em>iNOS</em>, <em>TGF-&beta;1</em>, <em>MCP-1</em>, and <em>NF-&kappa;B</em>, the pro-apoptotic gene <em>Bax</em>, and the anti-apoptotic gene <em>Bcl2</em> were assessed in colon tissues to evaluate the effectiveness of oleuropein treatment. Oleuropein was effective on reducing the mortality rate and disease activity index. Oleuropein caused a significant reduction in colon MDA, MPO, and NO levels and a significant elevation in SOD, CAT, and GPX levels and induced the down regulation of analyzed proinflammatory cytokines. Also, downregulation of <em>Bax</em> and upregulation of <em>Bcl2</em> were observed as a result of oleuropein treatment in comparison with untreated acetic acid induced ulcerative colitis group. Oleuropein showed intestinal anti-inflammatory, antioxidant, and anti-apoptotic effects in ulcerative colitis experimental model.</p> Ulcerative colitis, oleuropein, anti-inflammatory, antioxidant, Bax, Bcl2 224 233 http://ijmcmed.org/browse.php?a_code=A-10-2643-1&slc_lang=en&sid=1 Muhammed Hassan Motawea 100319475328460018963 100319475328460018963 No Biochemistry Department, Faculty of Science, Tanta University, Egypt. Hussein Abd Elmaksoud Ali 100319475328460018964 100319475328460018964 No Biochemistry Department, Benha University, Egypt. Mohamed Gamal Elharrif al_harrif@yahoo.com 100319475328460018965 100319475328460018965 Yes Department of Basic Medical Sciences, Shaqra University, KSA. Afaf Abd Elmajeed Desoky 100319475328460018966 100319475328460018966 No Biochemistry Department, Benha University, Egypt. Asmaa Ibrahimi 100319475328460018967 100319475328460018967 No Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat, Egypt.