Calendula arvensis L. is used in traditional folk medicine for the treatment of several diseases. Leaves, stems, and flowers of C. arvensis were extracted using a Soxhlet extractor with different solvents (i.e., hexane, chloroform, ethyl acetate, and methanol). The ethyl acetate extract of C. arvensis flowers (CAF EtOAC) had cytotoxic activity against MCF-7 and MDA-MB-231 breast cancer cells, with IC50 values of 70 and 78 µg/mL, respectively. Microscopic examination revealed concentration-dependent cell shrinkage, cell detachment, nuclear fragmentation, and chromatin condensation. The CAF EtOAC inhibited the migration of cultured cells in a scratch wounding assay, indicating a possible defense against metastasis. The same extract also caused apoptosis by downregulating Bcl-2 and upregulating Bax and caspase 3/7 activity. Phytochemical analyses revealed the presence of phenols and flavonoids, and gas chromatography-mass spectroscopy (GC-MS) revealed a high content of linolenic acid in the extract. Based on our data, the CAF EtOAC may provide active ingredients for the development of novel chemotherapeutics for breast cancer therapy.
Keywords: Apoptosis; Breast cancer; Calendula arvensis; Cell migration; GC-MS analysis.