Ultrastructural changes induced by açaí (Euterpe oleracea Mart) in MCF-7 breast cancer cell line

ABSTRACT

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.

KEYWORDS:

• Ultrastructural changes
• açaí
• MCF-7
• autophagy

Abbreviations

AO: acridine orange; AVOs: acidic vesicular organelles; DMEM: Dulbecco’s modi- 522 fied Eagle’s medium; MTT: 3-(4,5- 523 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; ROS: reactive oxygen species; TEM: Transmission electron microscopy

Acknowledgments

We thank the access to equipment and assistance provided by Microscopy and Imaging Center of the Piracicaba Dental School of the State University of Campinas. We thank to Flávia Sammartino for providing assistance in TEM analysis.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author Contributions

“Conceptualization, M.A.C.N.S, M.C.L.B, M.d.S.B.N and J.E.C.; methodology, M.A.C.N.S, C.S.S, K.R.A.B, L.A.S.W, M.d.S.B.N and J.E.C.; formal analysis, M.A.C.N.S.; writing—original draft preparation, M.A.C.N.S; writing—review and editing, M.A.C.N.S, M.d.S.B.N and J.E.C; funding acquisition, M.C.L.B. All authors have read and agreed to the published version of the manuscript.”

Data Availability Statement

The data and materials are available with the researchers at Faculty of Medical Science, UNICAMP. All datasets presented in this study are included in the article (www.fcm.unicamp.br).

Additional information

Funding

This research was funded by Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Estado do Maranhão, Notice 002/2019Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do MaranhãoFundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão [002/2019]