Comparative Effects of Different Doses of Dextran Sodium Sulfate on the Induction of Chronic Colitis in C57BL /6 Mice

IBD is a multifactorial disease in two general titles of Crohn's disease and ulcerative colitis. Animal models have provided extensive tools for identifying the underlying causes of the disease. Several methods, including the use of chemical compounds, have been introduced to induce animal model of colitis. In the present study, C57BL / 6 strains were used to induce colitis using dextran sodium sulfate (DSS) and due to the effect of the amount of this substance in the severity of clinical sign and survival, the effects of different doses of 1.5, 2, and 3% DSS were evaluated to create a mouse model in different groups.

In the current experimental study, to induce colitis, mice were divided into four case and control groups (5 mice in each group) and DSS was administrated in drinking water for 4 days and followed for 7 days with normal water. To create a chronic disease model, this process was repeated over three cycles. Clinical manifestations of colitis in mice were monitored daily including weight loss, bleeding, and diarrhea. The mice were sacrificed on day 34 and examined under microscopic and macroscopic examinations. The results of the study were analyzed and reported using Graph pad Prism 5 software.

In the DSS-3% group, high incidence of mortality with severe clinical symptoms was observed in 4 out of 5 mice in the study group (p-value <0.05), but in the DSS-1.5% group there was no significant difference in comparison with the healthy group. In addition, administration of 2% DSS resulted in the induction of moderate to no-mortality colitis in mice.

It seems that using 2% DSS with the proposed protocol can induce experimental colitis in female C57BL / 6 mice as an optimal dose.