Açai (Euterpe oleracea Mart.) feeding attenuates dimethylhydrazine-induced rat colon carcinogenesis

•The beneficial effect of spray-dried açai powder (AP) on chemically induced rat colon carcinogenesis was investigated.•Intake of AP at 5.0% inhibited the development of aberrant crypt foci and colon tumours.•Tumor cell proliferation and growth indices were modified by dietary AP at 5.0%.•AP is a potentially functional food that protects against colon carcinogenesis.

This study investigated the protective effect of spray-dried açaí powder (AP) intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats. After 4 weeks of DMH administrations, the groups were fed with standard diet, a diet containing 2.5% or 5.0% AP or a diet containing 0.2% N-acetylcysteine (NAC) for 10 weeks, using aberrant crypt foci (ACF) as the endpoint. Additionally, two groups were fed with standard diet or a diet containing 5.0% AP for 20 weeks, using colon tumors as the endpoint. In ACF assay, a reduction in the number of aberrant crypts (ACs) and ACF (1-3 AC) were observed in the groups fed with 5.0% AP (37% AC and 47% ACF inhibition, p = 0.036) and 0.2% NAC (39% AC and 41% ACF inhibition, p = 0.042). In tumor assay, a reduction in the number of invasive tumors (p < 0.005) and tumor multiplicity (p = 0.001) was observed in the group fed with 5.0% AP. Also, a reduction in tumor Ki-67 cell proliferation (p = 0.003) and net growth index (p = 0.001) was observed in the group fed with 5.0% AP. Therefore the findings of this study indicate that AP feeding may reduce the development of chemically-induced rat colon carcinogenesis.