Açaí Berries Inhibit Colon Tumorigenesis in Azoxymethane/Dextran Sulfate Sodium-Treated Mice

Background/Aims: The aim of this study was to investigate the protective effect of acai against azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colorectal cancer development. Methods: The effect of acai on tumorigenesis was assessed by evaluating tumor incidence, multiplicity and invasiveness in the mouse colon. The levels of myeloperoxidase (MPO) and proinflammatory cytokines (tumor necrosis factor α [TNF-α], interleukin [IL]-1β, and IL-6) were measured via enzyme-linked immunosorbent assay. Protein levels of cyclooxygenase 2 (COX-2), proliferating cell nuclear antigen (PCNA), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated death promoter (Bad) and cleaved-caspase-3 were assessed by immunoblotting. Results: Administration of pellets containing 5% acai powder reduced the incidences of both colonic adenoma and cancer (adenoma, 23.1% vs 76.9%, respectively, p=0.006; cancer, 15.4% vs 76.9%, respectively, p=0.002). In the acai-treated mice, the MPO, TNF-α, IL-1β and IL-6 levels in the colon were significantly down-regulated. Acai inhibited PCNA and Bcl-2 expression and increased Bad and cleaved-caspase-3 expression. In vitro studies demonstrated that acai treatment reduced lipopolysaccharide-induced expression of TNF-α, IL-1β, IL-6 and COX-2 in murine macrophage RAW 264.7 cells. Conclusions: Acai demonstrated protective effects against AOM/DSS-induced colon carcinogenesis, which suggests that the intake of acai may be beneficial for the prevention of human colon cancer.