Role of Oxidative Stress and Inflammatory Cytokines (TNF-α and IL-6) in Acetic Acid-Induced Ulcerative Colitis in Rats: Ameliorated by <i>Otostegia fruticosa</i>

Abstract

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that causes irritation, inflammation, and ulceration in the linings of the colon and rectum. Otostegia fruticosa is traditionally used to treat various disorders in different parts of the Middle East and sub-Saharan Africa. In the present study, we evaluated the ameliorative effects of crude leaves extract of O. fruticosa (OF.Cr) on acetic acid (AA)-induced UC model in Wistar albino rats. Wistar rats were administered orally with either vehicle (10 mL/kg), OF.Cr (200 and 400 mg/kg), or prednisolone (2 mg/kg) once a day for 6 days. On day 6, UC was induced in rats by intrarectal administration of a single dose of 5% AA (1.0 mL). Disease activity index (DAI) was recorded after one day of colitis induction by assessing the symptoms of colitis and then the rats were euthanized by cervical dislocation, and colon tissues were isolated for the histopathological examination and biochemical analysis of oxidative stress parameters and cytokines (Interleukin-6 and Tumor Necrosis Factor-α). OF.Cr pretreatment exhibits significant prevention against UC, as confirmed by a significant decrease of DAI, colonic ulceration, and reduced inflammatory score as compared to the AA-induced colitis rats. Depletion of total glutathione (GSH) levels and catalase (CAT) activities in the colitis group was significantly restored in the OF.Cr treated groups, while increased lipid peroxidation in the colon tissues was significantly reduced. OF.Cr prevented the activation of the IL-6 and TNF-α pathways in the colonic tissues, which were clearly observed by the decreased levels of IL-6 and TNF-α in the OF.Cr treated animals. Hence, OF.Cr could be developed in the future for the treatment of UC.

Keywords

• acetic acid
• Ulcerative colitis
• <i>Otostegia fruticosa</i>
• IL-6
• oxidative stress