Antiproliferative Effects of Various Furanoacridones Isolated from Ruta graveolens on Human Breast Cancer Cell Lines

Abstract

Background/aim: Thanks to its biologically active constituents, Ruta graveolens L. (Rutaceae) is a widely used medicinal plant. In our study, six furanoacridone alkaloids isolated from Ruta graveolens were investigated for their antiproliferative and pro-apoptotic effects on human breast cancer cell lines (MCF-7, MDA-MB-361, MDA-MB-231 and T47D).

Materials and methods: The cell lines were pretreated with alkaloid components (rutacridone, isogravacridone chlorine (IGC), gravacridonediol monomethyl ether, gravacridonediol, gravacridonetriol, a 1:1 mixture of gravacridonetriol and - diol monoglucosides) and their antiproliferative effects were determined by the MTT assay.

Results: IGC had the most marked effect on cell proliferation of MDA-MB-231 (half maximal inhibitory concentration (IC50)=2.27 μM). Cell-cycle analysis was applied to quantify the effect of IGC on subpopulations of MDA-MB-231 and MCF-7 cells. It caused a cell-cycle disturbance by decreasing the G2/M and G0/G1 and increasing the S phase and the appearance of the subdiploid (sub-G1) population. Hoechst 33258-propidium iodide staining was used to evaluate the morphological changes in IGC-pretreated MDA-MB-231 and MCF-7 cells, revealing the appearance of apoptotic features. IGC was found to cause a modest activation of caspase-3 and -9, but not caspase-8, indicating the activation of an intrinsic apoptotic pathway in MDA-MB-231 cells.

Conclusions: These in vitro findings indicate that furanoacridones are suitable candidates for anticancer drug development.

Keywords: Ruta graveolens L.; acridone alkaloids; antitumor effect; apoptosis; furanoacridones.