Figure 1: Experimental colitis was induced by administration of DNBS, followed by LSA injection. Firstly, colitis was induced in Balb/c mice by rectal instillation of DNBS followed by regular injection of LSA (L4 somatic antigen) for four times a week (1, 3, 5, 7, 9, 11, and 13). For the experiment, mice were randomly divided into 5 groups: I received 50% ethanol only (control); II was given DNBS only; III–V groups were injected with different concentrations of LSA (50 μg/mL, 100 μg/mL, and 200 μg/mL), respectively, until 14 days. The injection of LSA was started from day 1 until day 13. At the end of 14 days, mice in all groups were sacrificed. : 50% ethanol;: DNBS; ↕: LSA.