RESUMEN
Objective: To evaluate the antitumor effects of polyethylene glycol (PEG) microspheres with adsorbed Hancornia speciosa ethanolic extract (HSEE) on blood mononuclear (MN) cells co-cultured with MCF-7 breast cancer cells. Methods: PEG microspheres were adsorbed with HSEE and examined by flow cytometry and fluorescence microscopy. MCF-7 and MN cells obtained from volunteer donors were pre-incubated alone or co-cultured (MN and MCF-7 cells) for 24 h with or without HSEE, PEG microspheres or PEG adsorbed with HSEE (PEG-HSEE). Cell viability, superoxide release and superoxide dismutase were determined. Results: Fluorescence microscopy showed that PEG microspheres were able to absorb HSEE throughout their surface. Irrespective of the treatment, the viability index of MN cells, MCF-7 and their co-culture was not affected. Superoxide release increased in co-cultured cells treated with HSEE, adsorbed or not onto PEG microspheres. In co-cultured cells, SOD levels in culture supernatant increased in the treatment with HSEE, adsorbed onto PEG microspheres or not. Conclusion: HSEE has direct effects on MN cells co-cultured with MCF-7 cells. The results suggest the benefits of Hancornia speciosa fruit consumption by women at risk of breast cancer. In addition, because PEG-HSEE maintained oxidative balance in co-cultured cells, it is a promising alternative for the treatment of tumor cells.