Mechanisms Involved in the Antiproliferative and Proapoptotic Effects of Unsaponifiable Fraction of Extra Virgin Olive Oil on HT-29 Cancer Cells

Abstract

Extra virgin olive oil (EVOO) has demonstrated great oncostatic and antiinflammatory properties. Nowadays, it is clear that unsaponifiable fraction (UF) as well as other minor EVOO components have a key role in these beneficial effects. The present study was designed to evaluate UF effect in HT-29 human colon adenocarcinoma cells. Cell growth and viability assays were determined by sulphorhodamine B test at different time points (24, 48, and 72 h). The proapoptotic effect was evaluated by flow cytometric studies and different protein expression were determined by immunoblotting. UF μg/mL concentrations’ range significantly reduced the growth of HT-29 cell line. Moreover UF induced intrinsic apoptotic pathway in HT-29 human colon adenocarcinoma cells through PPARγ and NFκB signaling pathways coming up to COX-2 downregulation and modulating p53 suppressor protein levels. The results suggest that UF of EVOO may exert an important role in the anticancer effect of EVOO and provide a natural resource for the prevention or treatment of human colon cancer.

ACKNOWLEDGMENTS

This work was supported by funds from the Spanish Ministerio de Ciencia e Innovación (AGL 2008–02475, AGL 2011-26949) and Junta de Andalucía. Ana Cárdenogratefully acknowledges support from a Postgraduate National Program of FPU fellowship and financial sponsorship from the Spanish Ministerio de Educación. The authors gratefully acknowledge the assistance of Center for Technology and Innovation Research, University of Seville (CITIUS) and Instituto de la Grasa (Seville, Consejo Superior de Investigaciones Científicas).