Docosahexaenoic acid (DHA) alleviates inflammation and damage induced by experimental colitis

Abstract

Purpose Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic gastrointestinal disorders associated with significant morbidity and complications. This study investigates the therapeutic potential of docosahexaenoic acid (DHA) in a trinitrobenzene sulfonic acid (TNBS) induced colitis model, focusing on inflammation, oxidative stress, and intestinal membrane permeability. Methods Wistar albino rats were divided into Control, Colitis, and Colitis + DHA groups (n = 8–10/group). The Colitis and Colitis + DHA groups received TNBS intrarectally, while the Control group received saline. DHA (600 mg/kg/day) or saline was administered via gavage for six weeks. Macroscopic and microscopic evaluations of colon tissues were conducted. Parameters including occludin and ZO-1 expressions, myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH), total antioxidant status (TAS), total oxidant status (TOS), Interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) levels were measured in colon tissues. Results Colitis induction led to significantly higher macroscopic and microscopic damage scores, elevated TOS levels, reduced occludin and ZO-1 intensity, decreased mucosal thickness, and TAS levels compared to the Control group (p < 0.001). DHA administration significantly ameliorated these parameters (p < 0.001). MPO, MDA, TNF-α, and IL-6 levels were elevated in the Colitis group but significantly reduced in the DHA-treated group (p < 0.001 for MPO, MDA; p < 0.05 for TNF-α and IL-6). Conclusion DHA demonstrated antioxidant and anti-inflammatory effects by reducing reactive oxygen species production, enhancing TAS capacity, preserving GSH content, decreasing proinflammatory cytokine levels, preventing neutrophil infiltration, reducing shedding in colon epithelium, and improving gland structure and mucosal membrane integrity. DHA also upregulated the expressions of occludin and ZO-1, critical for barrier function. Thus, DHA administration may offer a therapeutic strategy or supplement to mitigate colitis-induced adverse effects.