Cytotoxic and HPLC-based analysis of eleven Rumex extracts: Anthraquinone profiling and synergistic potential with doxorubicin in cancer cells

The genus Rumex is a rich source of bioactive anthraquinones with known pharmacological properties, including anticancer potential. In this study, dichloromethane extracts of eleven Rumex species were tested on MCF-7, SK-BR-3, and MDA-MB-231 breast cancer cell lines for the evaluation of their cytotoxic properties. Among the tested species, the dichloromethane extract of Rumex crispus roots (DERCR) demonstrated the most potent cytotoxicity, particularly towards SK-BR-3 cells, with a survival rate of 54.56 % at 30 mu g/mL and was taken to the further studies in order to determine its modes of action. The DERCR did not induce a significant change in the cell cycle phases of SK-BR-3 cells while generating reactive oxygen species (ROS) leading to apoptosis and necrosis. Furthemore, the combination regimens of the DERCRs with doxorubicin were also applied to the cancer cells to see if there is a possible synergistic effect in cancer cell lines. No synergistic effects were observed. High-performance liquid chromatography (HPLC) was used to identify and quantify major anthraquinone compounds in the composition of each extract. Thus, the Rumex species based on the substantial anthraquinone derivatives in their composition were assessed in terms of their cytotoxicity. The findings supported R. crispus including anthraquinones as a complementary agent in breast cancer therapy.