Apple Polysaccharide Reduces Nf-Kb Mediated Colitis-Associated Colon Carcinogenesis

Abstract

Nuclear factor-kappa B (NF-κB) is an important molecule in mediating inflammatory colitis, which can lead to colorectal cancer (CRC). The aim of this study was to evaluate the chemopreventive efficacy of apple polysaccharide extract (AP) in inhibiting NF-κB-mediated inflammation pathways in CRC. We evaluated AP in vitro in HT-29 and SW620 human CRC cells. We also used the azoxymethane and dextran sodium sulphate (AOM/DSS) model to induce colon carcinogenesis in vivo. The chemoprotective effects of AP were assessed using Western blot, immunofluorescence assay, real-time PCR, electrophoretic mobility shift assay, and flow cytometry. AP reduced AOM/DSS-associated toxicities, prevented carcinogenesis, and decreased the expression of TLR4, MD2, MyD88, TRAM, TRIF-related adapter molecule, interferon-β, tumor necrosis factor-α, and interleukin-6. The protective effects of AP may be related to the inhibition of TLR4/MD2-mediated signaling, including MyD88 and TRIF, as well as the inhibition of NF-κB-mediated inflammatory signaling pathways. Therefore, AP could be used in combination therapy for the prevention of colitis-associated colon cancer.

FUNDING

This investigation was supported by grants (No. 81072671, No. 81302787) from National Natural Science Foundation of China, a grant (No. 2014JQ4152) from the Technology Gallery of Shaanxi Province, and grant 12FZ03 from Xi’an Medical University projects. Dian Zhang, Man Mi, and Fengliang Jiang contributed equally to this work.

SUPPLEMENTAL MATERIALS

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