BACKGROUND:Anthocyanins, flavonoids and organic acids widely occurring in extracts of the fruits of Aristotelia chilensis ("Maqui"), concertedly acts on the expression of cyclooxygenase-2 (COX-2), NF-κB, HT-29 and Caco-2 colon cancer cell growth inhibition and on the production of inflammatory mediators. OBJECTIVE: To assess the anti-inflammatory effects of extracts from fruits of "Maqui Berry", on the HT-29 and Caco-2 human colorectal cancer cell lines by measuring COX-2 and NF-κB as well as their antioxidant activities. MATERIALANDMETHODS: Methanol/water extracts and its partitions (acetone and ethyl acetate) from three varieties of "Maqui" were used to access their effects on growth of HT-29 and Caco-2 colon cancer cells, COX-2, NF-κB, NO formation, oxidations by DPPH, TBARS, FRAP and ORAC. RESULTS: Fractions rich in anthocyanins, exhibited potent chemoprotective abilities on decreasing growth of HT-29 and Caco-2 colon cancer cells. The results indicated that the extracts suppressed the production of nitric oxide (NO), through the down-regulation of inducible nitric oxide synthases (iNOS). The structural features of the extracts correlate with the inhibition of NF-κB and COX-2 protein expressions and a potent antioxidant activity by assays of DPPH, FRAP, TBARS and ORAC. The inhibition of cell growth and NO production by selected extracts was dose-dependent with significant effects seen at concentration as low as 25.0 and 10.0 ppm, respectively. CONCLUSIONS: The phenolics (anthocyanins, flavonoids, and organic acids) that occur in extracts from Maqui berry Aristotelia chilensis may provide therapeutic potential against colon cancer.