Isolation of oleanolic acid from Lavandula stoechas and its potent anticancer properties against MCF-7 cancer cells via induced apoptosis

Medicinal plants are natural resources of diversified therapeutic metabolites. Lavandula stoechas has been used traditionally for the management of different metabolic disorders. However, studies on the anticancer characteristics of certain bioactive compounds present in this plant are very limited. In view of this, the aim of the present study was to isolate oleanolic acid (a triterpenoid) from L. stoechas and assess its anticancer trait against breast carcinoma cells (MCF-7) via induced apoptosis. Initially, oleanolic acid was isolated from the ethyl acetate fraction of L. stoechas using standard extraction protocols. Furthermore, the structure of compound was established using mass spectrometry, FT-IR, 1H NMR, and 2D NMR (HSQC) techniques. In vitro antiproliferative effect of oleanolic acid was assessed against breast carcinoma cells (MCF-7 and MDA-MB-231) and non-cancerous cells (BHK-21) using the MTT assay. Oleanolic acid showed prominent cytotoxicity of 72.44 ± 3.33 and 78.55 ± 2.67 % against MCF-7 and MDA-MB-231 cells with IC50 values of 13.09 and 160.22 µg/mL, respectively. Moreover, the compound showed negligible toxicity against the BHK-21 cell line. Furthermore, the apoptotic features in oleanolic acid-treated MCF-7 cells were determined using fluorescent microscopy, which showed typical nuclear condensation, increased ROS generation, and the loss of outer mitochondrial membrane potentials. The levels of activated caspases in MCF-7 cancer cells were estimated using a fluorescent kit, showing a significant increment in caspase-9 and caspase-7 for oleanolic acid-treated MCF-7 cells. Moreover, oleanolic acid showed down-regulation of the Bcl2 and PDGF genes. Our findings demonstrated the pivotal role of oleanolic acid as pronounced anticancer agent against MCF-7 cell lines by inducing apoptotic mechanism via intrinsic pathway.