A total of 70 BALB/C mice [weight (20.0±2.0) g, 8-week years old, female, pathogen free] were randomly divided into 7 groups: a normal group, a model group, a
mesalazine treatment group, a
prednisone treatment group, a low-dose
novaferon group, a middle-dose
novaferon group and a high-dose
novaferon group (10 mice per group). The normal group-mice were given distilled water. The
ulcerative colitis model was established by treated the mice with 4% DSS for 7 continuous days. At the 8th day, the mice in the all of
drug treatment groups were injected corresponding drugs (i.p.). During the experiment, the general situation, daily weight, stool trait and occult blood were recorded, and the mice were killed on the 14th day. The disease activity index (DAI), colon length, histological scores were assessed. Immunohistochemistry was used to measure the expression of TNF-α in colonic mucosa.
RESULTS: 1) The mice treated with DSS
solution showed
diarrhea, mucous stool and bloody stool, and the DAI score increased gradually. The
mesalazine, predinison and nofaferon could ameliorate the general situation of the mice, reduce the DAI and histological scores, and reverse the decrease in the colon length. 2) Compared with the model group, the DAI scores were significantly decreased in the
novaferon groups (at low, middle or high dose), the
mesalazine group or the
prednisone group (all P<0.01), but there was no difference among the
mesalazine group, the
prednisone group and the low-dose
novaferon group (all P>0.05). The efficacy of
novaferon in the middle-dose group and the high-dose group are better than that in the
mesalazine group, the
prednisone group and the low-dose
novaferon group (all P<0.01). The efficacy of
novaferon showed a dose-dependent manner. 3) The injury of colonic mucosa was relatively mild in the
novaferon groups (at low-dose, middle-dose or high-dose), the
mesalazine group and the
prednisone group, and there were partial glands and less inflammatory cells. Compared with the model group, there was statistics difference (all P<0.05). The tissue injury was significantly alleviated, and the DAI score was decreased in the high-dose
novaferon group compared the middle-dose
novaferon group (P<0.05), but there was no significant difference between the low-dose
novaferon group and the middle-dose
novaferon group or between the
mesalazine group and the
prednisone group (both P>0.05). 4) The TNF-α expression was significantly down-regulated in the
novaferon groups (at low-dose, middle-dose or high-dose), the
mesalazine group and the
prednisone group compared with model group (all P<0.01); but there was no significant difference between the
mesalazine group and the
prednisone group (P>0.05); the decrease of TNF-α expression by
novaferon displayed a dose-dependent manner. Compared with the
mesalazine group or the
prednisone group, the TNF-α expression in
novaferon groups at all dosages was dramatically reduced (all P<0.01).
CONCLUSION: