Magnolia dealbata seeds extract exert cytotoxic and chemopreventive effects on MDA-MB231 breast cancer cells

Abstract

Context: Cancer prevention remains a high priority for the scientific world. Magnolia dealbata Zucc (Magnoliaceae), a Mexican endemic species, is used for the empirical treatment of cancer.

Objective: To evaluate the cytotoxic and cancer chemopreventive effects of an ethanol extract of Magnolia dealbata seeds (MDE).

Materials and methods: The cytotoxic effect of MDE, at concentrations ranging from 1 to 200 µg/ml, on human cancer cells and human nontumorigenic cells was evaluated using the MTT assay for 48 h. The apoptotic activities of MDE 25 μg/ml on MDA-MB231 breast cancer cells were evaluated using the TUNEL assay and the detection of caspase 3 using immunofluorescence analysis for 48 h, each. The chemopreventive effect was evaluated by administrating different doses of MDE, between 1 and 50 mg/kg, injected intraperitoneally daily into athymic mice which were implanted with MDA-MB231 cells during 28 days. The growth and weight of tumors were measured.

Results: MDE showed cytotoxic effects on MDA-MB231 cells (IC₅₀ = 25 µg/ml) and exerted pro-apoptotic activities as determined by DNA fragmentation in MDA-MB231 cells. MDE 25 µg/ml also induces the activation of caspase 3 in MDA-MB231 cells. These results suggest that Magnolia dealbata may be an optimal source of the bioactive compounds: honokiol (HK) and magnolol (MG). MDE 50 mg/kg i.p. exerted chemopreventive effects by inhibiting the growth of MDA-MB231 tumor by 75% in athymic mice, compared to the control group.

Conclusions: MDE exerts cytotoxic, apoptotic and chemopreventive activities on MDA-MB231 human cancer cells.

• Apoptotic
• athymic mice
• caspase 3
• Magnoliaceae

Acknowledgements

A.J.A.C. (174493) and I.G.S. (226748) were provided with graduate fellowships from CONACYT. We acknowledge generous grant support from Instituto de Ciencia y Tecnología del Gobierno del Distrito Federal (ICyT-GDF; GI/PIFUTP08-142 to A.G.C.), and Consejo Nacional de Ciencia y Tecnología- México (CONACYT-México Grant 127822 to A.G.C.).