CITOTOXIC EFFECTS OF NANOEMULSIONS BASED ON BURITI OIL (MAURITIA FLEXUOSA) ON HUMAN MAMMARY CANCER CELLS

The aim of this study was to analyze the effects of Buriti oil (Mauritia flexuosa), free or incorporated in nanoemulsions, against a human mammary cancer cell (MCF-7) in vitro. Buriti oil nanoemulsions (BuNE) were prepared as following: different proportions of Buriti oil and surfactants were added in deionized water (for negatively charged BuNE-) or chitosan solution (for positively charged BuNE+) and submitted to sonication (20Hz) for 5 minutes under an ice bath. Physicochemical parameters of BuNEs were analyzed by dynamic light scattering. Cytotoxic effects of the nanoemulsions obtained were evaluated in human mammary cancer cell line (MCF-7) by MTT assay. Briefly, cells were seeded in 96-well pates (5×103 cells/well) and incubated with 90&#956;g/mL and 180&#956;g/mL of free Buriti oil or BuNEs for 24h and 72h at 37oC in 5% CO2. Then, the culture medium was removed and 150&#956;L of MTT solution (0.5mg/mL) were added. After 2h, the MTT solution was removed and 100 µL of dimethyl sulfoxide were added. Cell viability evaluation was determined after reading the absorbance at a wavelength of 595nm. Statistical analysis was performed with ANOVA (Tukey test). Both BuNEs obtained showed a mean hydrodynamic diameter &#8804;190nm and medium polydispersity index &#8804;0.2. MCF-7 cell viability was significantly reduced in a dose-dependent fashion when incubated with both negatively or positively charged BuNEs. The higher dose evaluated (180&#956;g/mL) decreased cell viability in approximately 50% after 24 and 72h (p<0.05). Interestingly, no significant cytotoxic effects were observed when MCF-7 cells were treated with different concentrations of free oil. In conclusion, the present data highlight how nanotechnology approaches contribute to increase Buriti oil bioavailability enabling its application as a putative antitumoral agent. In addition, both BuNEs evaluated present cytotoxic effects against human mammary cancer cells and are promising candidates to be employed as adjuvant tools in conventional breast cancer therapies.