| Along with the incidence rate of ulcerative colitis(UC)rise,ulcerative colitis related colorectal cancer(UCRCC)also appears extremely importantly.Due to the serious adverse reactions,many chemotherapeutic drugs resulting in short survival time and poor prognosis.Therefore,it is necessary to develop more effective and safe therapeutic agents for cancer.Because of its high biological activity and low toxicity,the natural medicine provides a novel perspective for the treatment of cancer.In our previous studies,we found compound dracorhodin enema was helpful to UC,to investigate the therapeutic effects of which in UCRCC,we developed a model of UCRCC in mice.The mechanism of the Chinese drugs pharmaceutics preventing UCRCC was discussed by observing the changes of β-catenin,C-myc and PCNA in colon mucosa.In our experiment,sixty male BALB/c mice were randomly divided into four groups: a normal group,a model group,a low dose of compound dracorhodin enema treatment group and a high dose treatment group.All the mice were fed adaptively for a week,and then the normal group sustained feeding with distilled water,the other groups were fed according to AOM(azoxymethane)/ DSS(dextran sodium sulphate).The two treatment groups were treated with different dosage(13ml/kg,26ml/kg)of compound dracorhodin enema from day 1.Disease activity index(DAI)was evaluated daily during the experiment.Mice were sacrificed after 10 weeks,from which the colons and rectums were removed.The colon histomorphology was assayed by naked eyes and microscope.The expressions of β-catenin,C-myc and PCNA were detected by Western-blot,Quantitative Real-time PCR and immunohistochemistry.Our results shew that there were no abnormal sign by naked eyes and light microscope in normal control group.In the model group,extensive erosion,ulcer and polyps were found,especially in the distal colon;extensive necrosis,erosion,a large number of inflammatory cell infiltration,different degrees of intraepithelial neoplasia and carcinoma were seen under microscope.In the treatment group,mucosal congestion,edema,necrosis and erosion were observed,and the number of polyps was reduced;erosion,necrosis,inflammatory cell,glandular atrophy,different degrees of intraepithelial neoplasia and a small amount of carcinoma were found under the microscope.At the end of the 1st,2nd,3rd cycle,compared with normal group,the DAI scores were significantly higher in model group and treatment groups(P<0.05),the DAI scores in the treatment groups were significantly lower than which in model group(P<0.05),but there was no significant difference between high and low dose of compound dracorhodin enema treatment groups(P>0.05).The result of immunohistochemical staining shew that the positive expression of β-catenin were in the membrane in the normal group,but mainly in the cytoplasm and/or nucleus in the model group,the positive rate of mice in the model group was 92.3% with statistical significance as compared with the normal group(P<0.05);in the high and low treatment groups,the positive expression of β-catenin in the nucleus was on the decline and appeared mainly in the membrane and cytoplasm,the positive rate in mice was 66.7% and 80.0% with statistical significance as compared with the model group and the control group(P<0.05).Compared with the normal group,nucleus localization of β-catenin in model group,high dose and low dose treatment group(1.826±0.192,1.049±0.108,1.063±0.144)were dramatically increased.The abundance of C-myc(0.933±0.105,0.620±0.079,0.615±0.083)and PCNA(0.238±0.026,0.132±0.016,0.136±0.021)were also significantly increased(P<0.05).Compared with the model group,nucleus localization of β-catenin and protein abundance of C-myc and PCNA were significantly decreased(P<0.05).There was no significant difference between the two treatment groups(P>0.05).QRT-PCR results shew that,there were no significance of the mRNA level of β-catenin in the four groups(0.098±0.087,1.071±0.110,1.025±0.082,1.063±0.104).The mRNA level of C-myc(6.312±0.335,2.735±0.143,2.820±0.179)and PCNA(4.928±0.296,2.453±0.163,2.336±0.171)in the model group and the high dose,low dose treatment groups were dramatically increased as compared with the normal group(P<0.05).Compared with the model group,the abundance of C-myc and PCNA mRNA were significantly decreased(P<0.05).There was no significant difference between the two treatment groups(P>0.05).We can conclude that: 1.Compound dracorhodin enema reduced malignant transformation of experimental ulcerative colitis without dose-dependent.2.The Wnt/β-catenin pathway plays an important role in the occurrence of UCRCC.3.Compound dracorhodin enema can inhibit the Wnt/β-catenin pathway through preventing the translocation of β-catenin to nucleus. |
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