Molecular mechanism of curcumin combined with 5-aminosalicylic acid-mediated Notch signaling pathway in the treatment of ulcerative colitis rats

ObjectiveTo explore the possible role of Notch signaling pathway in the pathogenesis of ulcerative colitis (UC) in rats and the molecular mechanism of curcumin treating UC in rats through Notch signaling pathway.

MethodsA rat UC model was prepared by injecting 2 mL/kg of trinitrobenzenesulfonic acid into the colon.There were five groups including control group, UC model group, 5-aminosalicylic acid (5-ASA) group, curcumin group, and curcumin+5-ASA group, with 6 rats in each group.The last three groups were applied intragastrically once a day for 10 consecutive days.Meanwhile, the general condition of rats was observed daily, and the disease activity index was recorded.After 10 days of treatment, the colonic tissues of rats was taken to carry out the colonic mucosa damage?index score and HE staining for observing the colonic mucosal injury of rats; immunohistochemistry and Western blotting were used to detect the protein expression of Notch1, jaggled1, and Hes1 in rat colonic mucosa; RT-PCR was applied to analyze the mRNA expression of Notch1, jaggled1, and Hes1 in rat colonic mucosa.

ResultsThe HE staining results showed that there appeared significant pathological damage in the model group compared to the control group, and the pathological damage in the 5-ASA group and curcumin group was alleviated (P<0.01); the alleviated pathological damage in the curcumin+5-ASA group was the most obvious (P<0.01).The results of immunohistochemistry, Western blotting, and RT-PCR showed that compared with the control group, the mRNA expression levels of Notch1, jaggledl, and Hes1 in the model group increased (P<0.01); compared with the model group, the expression of Notch1, jaggledl, and Hes1 in the mucosal tissue of rats in the 5-ASA group and curcumin group decreased (P<0.01), and the decrease level in Notch1, jaggledl, and Hes1 was most significant in the curcumin+5-ASA group (P<0.01).

ConclusionsCurcumin has a certain therapeutic effect on UC, which may be related to its involvement in mediating the Notch signaling pathway.