Jaboticaba peel extracts inhibit MCF7 and MDA-MB-231 breast cancer cells.

There is increased interest in natural products and derivate due their potential cancer preventive as well as therapeutic properties. Breast cancer is one of the most common cancers in women. Jaboticaba peel (Myrciaria jaboticaba) is a concentrate source of bioactives with related to several health benefits. The aim was investigate the anticancer activity of different extracts of Jaboticaba peel in human breast cancer cell lines. MCF7 and MDA-MB-231 lines were treated with Polar (JP) or Non-Polar (JN) extract of Jaboticaba peel. Honokiol was used to treat the control group (HC), this is a natural phenolic compound isolated from seed cones from Magnolia grandiflora. Parameters of cell viability, growth, migration and apoptosis were assessed. Both extracts inhibited the colony formation of the most invasive cell cancer line (MDA-MB-231), and JN was effective also in MCF7. According to soft-agar assay, JN reduced anchorage-independent growth of both line cells, and JP acted in MCF7. Cell-viability assay was performed by estimating the reduction of MTT. JN extract reduced the cell viability after 24 h incubation with results similar to HC. JN and JP were able to reduce the cell migration according to scratch-assay of MCF7, JN has also decreased the migration of MDA-MB-231. Matrigel invasion assay was used as model system of metastasis, JN has highlighted, it showed lower invasion than MDA-MB-231. In order to show the possible mechanisms involved, apoptotic and reticulum stress pathways were analyzed by Western-Blotting and PCR. JN increased the cPARP, BAX, phosphorylated-ERK level. This extract has also increased the CHOP protein expression, showing the apoptosis induction. Both extracts, JN and JP, have enlarged the reticulum stress, evidenced by higher level of IRE-1α and BIP proteins. Therefore, jaboticaba peels, mainly non-polar compounds, have antitumor effects in breast cancer cell lines by inhibition of growth, viability and invasion.