EFFECTS OF BURITI OIL (MAURITIA FLEXUOSA) NANOEMULSIONS ON PROLIFERATION, MORPHOLOGY, AND CELL DEATH OF BREAST CANCER CELLS IN VITRO

SAMPAIO, M. C., COSTA, P. C., OMBREDANE, A. S., AZEVEDO, R. B., JOANITTI, G. A.

Universidade de BrasíliaThe purpose of this study was to evaluate the biological effects of buriti oil (Mauritia flexuosa) nanoemulsions (BuNEs) on breast cancer cells MCF-7 in vitro regarding cell proliferation, morphology, and cell death characteristics.Flow cytometry was performed to investigate the possible mechanisms of cell death after 24 hours of exposure with negative buriti oil nanoemulsion (BuNE-) and buriti oil nanoemulsion with N-(2,3-Dioleoyloxy-1-propyl) trimetilammonium–DOTAP- (BuNE+DOTAP) at 360 μg/mL. The phosphatidylserine exposure was analyzed using Annexin V-FITC and Propidium Iodide (PI) as markers for apoptosis and necrosis, respectively. DNA fragmentation and cell cycle pattern were also evaluated by PI. Moreover, the mitochondrial membrane potential (MMP) was measured using the fluorochrome Rhodamine 123. For cell morphologic aspects, MCF-7 cells were seeded in 12-well plates (2×104) and were treated with BuNE-, BuNE+DOTAP and free buriti oil at 360 μg/mL for 24 hours. Cells were stained with 0,1% Giemsa in order to analyze their morphologic aspects. Statistical analysis was performed with ANOVA (Dunnett post-test) (p<0,05).After 24 hours of exposure with Annexin V-FITC or PI, MCF-7 cells treated with BuNE- and BuNE+DOTAP demonstrated significant increase of double marking of Annexin V-FITC and PI in ~50%, thus indicating late apoptosis and/or necrosis. However, MCF-7 cells did not show difference of MMP nor DNA fragmentation when compared with the control group after 24 hour of treatment. Interestingly, ~27% of the cells were arrested at S phase and ~18% at G2/M phase of the cell cycle when treated with BuNE-. Based on the stained cells, BuNE- lead to a shrinkage on the cell morphology, when compared with the group control.In conclusion, BuNEs induced cell death on breast cancer cells. In addition, MCF-7 cells had their cell cycle and morphologic pattern changed when treated with BuNE-. Thus, BuNEs are promising new adjuvant tools for breast cancer treatment.Brazilian palm tree, breast cancer, Buriti, Cell death, Nanodrug, Oil, Proliferation