Effects of krill oil on apoptotic pathways in rats with dextran sulfate sodium-induced ulcerative colitis

Objective: The aim of this study is to evaluate the effect of krill oil supplementation on apoptosis in a rat model of colitis experimentally induced by dextran sulfate sodium (DSS). Methods: A total of 28 male Wistar Albino rats were divided into four groups (n=7 per group): control, krill oil, DSS, and DSS+krill oil. To induce colitis, rats in the DSS and DSS+krill oil groups were exposed to DSS for 14 days, while the DSS+krill oil group additionally received krill oil supplementation. Throughout the experiment, body weight changes and Disease Activity Index (DAI) were monitored twice a week. At the end of the experiment, colons were excised, and their weights and lengths were recorded. Colonic tissue samples were analyzed using the ELISA method to determine total protein levels as well as the concentrations of caspase-3, -8, -9, TNF-α, Bax, and Bcl-2. Results: In the DSS-induced group, weight loss, disruption in colonic integrity, and increased DAI scores were observed, whereas krill oil supplementation alleviated these effects. The average colon length was 11,6 ± 0,9 cm in the DSS group and increased to 12,9 ± 0,5 cm in the DSS+krill oil group. Colon weight was significantly reduced in the DSS group (1,2 ± 0,1 g), and krill oil supplementation partially restored this reduction. Regarding apoptotic and inflammatory markers, DSS administration led to significant increases in caspase-3 (p<0,001), caspase-8 (p<0,001), caspase-9 (p<0,001), TNF-α (p<0,001), and Bax (p<0,001), while Bcl-2 levels significantly decreased (p<0,001). Conclusion: Krill oil demonstrated a protective effect on colonic mucosa in the DSS induced colitis model by suppressing apoptotic processes. It also mitigated impairments in parameters such as colon length and weight. These findings suggest that krill oil has potential as a supportive agent in the management of ulcerative colitis and provide novel contributions to the literature in this field. Keywords: ulcerative colitis, dextran sulfate sodium, krill oil, apoptosis