Effects And Mechanisms Of Soymilk And Fermented Soymilk In Rats Model With Ulcerative Colitis

Objective:To investigate the protective effects of soymilk and fermented soymilk on ulcerative colitis, ulcerative colitis model in rats was induced by Dextran sulfate sodium (DSS) in the study. To evaluate the efficacy and to explore the anti-inflammatory mechanism of soymilk and fermented soymilk treating ulcerative colitis by detecting the levels of TNF-α in the serum and IL-6, IL-10in the colon tissue, observing the expressions of TNF-α mRNA and nuclear factor-kappa Bp65mRNA (NF-κB p65) in the colon tissues.Method:Sixty-four male rats(SD) were randomly divided into eight groups:normal control group, model control group, low, middle, high dose of soymilk group and low, middle, high dose of fermented soymilk. Formed the model being induced, the rats in the treatment group received soymilk or fermented soymilk by gavage daily, while the remaining two groups received a treatment of physiological saline. The intervention group respectively with soymilk and fermented soymilk lavage.The rest of the two groups with equivalent physiological saline lavage.After1w, except the normal control group, the other groups were given5%DSS to induce ulcerative colitis model in rats. After3w, all the rats were killed. Duration of test, The DAI, macroscopical gross and histological damages of colon were evaluated.The myeloperoxidase(MPO), malondialdehyde(MDA), superoxide dismutase(SOD) and total antioxidant capacity(T-AOC) levels were examined in colon tissue homogenates and blood serum by biochemical methods. The serum concentration of TNF-α and the tissue level of IL-6and IL-10were measured by using enzyme-linked immunosorbent assay. The expressions of TNF-α mRNA and NF-κB p65mRNA in colonic tissues were measured with the methods of Real-time PCR.Results:Compared with normal control group, the model control group rats appeared diarrhea and hematochezia.1.Compared with the normal control group, the model control group appeared diarrhea and hematochezia. The DAI, gross scores and histological damages of colon tissues were notably reduced (P<0.01).2.Compared with the model control group, the scores of DAI, gross scores and histological damages were decreased obviously in the high dose of soymilk group and all fermented soymilk groups (P<0.05).3.Compared with the normal control group, the model control group significantly increased MPO(P<0.01)level of serum. In the meantime, significantly decreased SOD (P<0.01) and T-AOC (P<0.01) activities and decreased MDA (P<0.01) contents of serum and colon tissue.4.Compared with the model control group, the high dose of soymilk group and all fermented soymilk groups significantly decreased MPO(P<0.01)level of serum, significantly increased SOD (P<0.01) and T-AOC (P<0.05) activities and decreased MDA (P<0.05) contents of serum and colon tissue.All the fermented soymilk groups significantly decreased MPO(P<0.01)level of serum, significantly increased SOD (P<0.01) and T-AOC (P<0.01) activities and decreased MDA (P<0.01) contents of serum and colon tissue.5.Compared with the normal control group, the model control group and the low dose fermented soymilk group significantly decreased IL-6level(P<0.05) of colon tissue and TNF-α level of serum in UC rats. In the meantime, the medium and high dose fermented soymilk groups significantly increased IL-10(P<0.05) level and decreased TNF-α (P<0.01)contents and IL-6(P<0.01) level of colon tissue in rats.6.The expression of TNF-α mRNA and NF-κB p65mRNA in the model control group were significantly higher than normal control group (P<0.01). Compared with the model control group,all fermented soymilk group could decreased the expression of TNF-a mRNA(P<0.05). And the medium and high dose fermented soymilk groups significant decreased of the expression of NF-κB p65mRNA (P<0.05).Conclusion:1.Rat model of UC was induced successfully by5%DSS.2.With the administration of fermented soymilk, the clinical symptom of ulcerative colitis rats was relieved rapidly, the colon injury were alleviated, the ultramicro-pathology damage of colonic mucosa was restored, and the degrees of inflammation were obviously alleviated.3.The different effect between fermented soymilk and soymilk may be due to the different content.4.The treatment of fermented soymilk was effective on the UC rats. The antioxidative effect of fermented soymilk and soymilk of NF-κB p65may be the anti-inflammatory mechanism of fermented soymilk.