RESUMEN
Açaí (Euterpe oleracea Mart) is an Amazon plant with many biological properties. Previous report of this group evidenced autophagy induction after treatment with açaí seed extract in MCF-7 breast cancer cell lines by acridine orange assay. The aim of this study was to evaluate the ultrastructural changes induced by açaí seed extract in MCF-7 breast cancer cell lines. First, MCF- 7 breast cancer cell line viability was evaluated by MTT assay. Acridine orange assay showed increase in the acidic compartments, suggesting autophagolysosome formation. These cells were treated with 25 µg/ml for 24 h and evaluated by transmission electron microscopy (MET). This analysis showed that açaí seed extract induced autophagy, confirmed by autophagolysosome formation. Furthermore, açaí seed extract increased the number of mitochondria, suggesting the enrollment of reactive oxygen species in autophagy.