Evaluation of antitumoral effect of Hibiscus sabdariffa extract on human breast cancer cells.

BackgroundBreast cancer is the most frequent tumor in women. Natural substances represent an important source of innovative therapeutic solutions, eventually integrating or substituting conventional drugs and chemicals. Hibiscus sabdariffa L. is a plant of the Malvaceae family that has raised interest thanks to its anti-inflammatory, antioxidant and anticancer effects. In this work, we evaluated the antitumoral effects of an enriched fraction of Hibiscus sabdariffa L. extract (HsEF) in two human breast cancer cell lines, MCF-7(ERα +) and MDA-MB-231 (triple negative). Methods and resultsCell viability was assessed by MTT and Trypan blue assays. HsEF reduced both cell lines viability in a dose and time dependent manner and this effect results irreversible. In MCF-7 cells immunofluorescence experiments, demonstrated that HsEF induced ERα -location from nucleus to perinuclear area and in cytoplasmic compartment. qRT-PCR and western blotting high-lighted that HsEF reduced ERα, BRCA1 and caveolin1 gene and protein expression in MCF-7 cells, but not in MDA-MB-231 cells. Moreover, we demonstrated that HsEF reduced proteasome activity, an increased autophagy, impair migration and invasion in both cell lines. ConclusionsOur data suggest HsEF has an antitumoral effects on both breast tumor cells examined and that ERα involvement could explain the differences observed between the two cell lines.