Investigation of cytotoxic effects of various furanoacridones isolated from Ruta graveolens

Ruta graveolens L. (Rutaceae) is a widely used medicinal plant due to its constituents like furanocoumarins and rutoside. In our study, six furanoacridone alcaloids isolated from Ruta graveolens [1] were investigated on human breast cancer cell lines (MCF-7, MDA-MB-361, MDA-MB-231, T47D) for antiproliferative effects and further studies were employed in order to determine the effects on cell cycle and morphology. Breast cancer is by far the most frequent malignant disease among women and accountable for the most cancer-related deaths in the female population worldwide. These data support the urgent need for developing new antiproliferative agents with higher efficacy and better tolerability profile.

The cancer cell lines had been pretreated with the alkaloid components (rutacridone, isogravacridone chlorine (IGC), gravacridonediol monomethyl ether, gravacridonediol, gravacridonetriol, mixture of garvacridonetriol and diol monomethyl ether) and the antiproliferative effects were determined by MTT assay and IC₅₀ values were calculated. IGC had the most marked effect on cell proliferation of MDA-MB-231 (IC₅₀= 2.27 µM) and MCF-7 (IC₅₀= 4.55 µM). Flow cytometric cell cycle analysis had been applied in order to quantify the effect of IGC on the subpopulations of MDA-MB-231 and MCF-7 during cell cycle. It caused cell cycle disturbance decreasing G2/M and G0/G1 and increasing S phase. Hoechst 33258-propidium iodide dual staining was used for the evaluation of morphological changes in MDA-MB-231 and MCF-7 cells pretreated with IGC, resulting in the appearance of nuclear condensation. Caspase-3 activation was additionally determined from IGC-treated MDA-MB-231 cell in order to prove its apoptotic potential.

Based on these in vitro findings IGC could be considered for further in vitro and in vivo studies to characterize the mechanism of its antiproliferative action.

References:

[1] Réthy B et al. Planta Med 2007; 73: 41 – 48