Eupatilin Inhibits Cell Growth and Enhances Apoptotic Cell Death in MDA-MB-231 Breast Cancer Cells

Background Breast cancer is the most common type of cancer characterized by uncontrolled growth of cells in breast tissue, constituting the most prevalent cancer in females worldwide. Standard treatments, including surgery, radiation, chemotherapy, and hormonal therapy, often exhibit elevated recurrence rates and considerable drug toxicity, hence requiring the exploration of alternative strategies to enhance therapeutic results. Purpose This study examined the anti-cancer effects and underlying mechanisms of eupatilin against breast cancer MDA-MB-231 cells through the in vitro approach, and to understand the mechanisms of eupatilin, in silico approach was implemented by targeting B-cell lymphoma 2 (BCL-2) and cyclin-dependent kinase 6 (CDK6), a key regulator of cell survival and cycle progression. Materials and Methods The cytotoxicity of eupatilin at diverse dosages, that is, 5–100 µM, on breast cancer cells was studied using the MTT test. The influence of eupatilin on the cytoplasmic membrane integrity of breast cancer cells was scrutinized using the lactate dehydrogenase (LDH) release assay to evaluate the cytotoxic level. The dual staining test was conducted to examine the apoptosis-inducing capabilities of eupatilin on MDA-MB-231 cells. The molecular docking studies were carried out to predict key interactions of eupatilin with the defined targets BCL-2 and CDK6, which were then compared with the interactions of doxorubicin to understand its efficacy. Results The viability of breast cancer cells was significantly diminished following treatment with eupatilin at increasing concentrations. This was accompanied by a marked increase in LDH enzyme activity, indicating compromised membrane integrity and cellular damage, and indicating the cytotoxicity of eupatilin treatment. Furthermore, treatment with eupatilin increased apoptotic incidence in MDA-MB-231 cells, as demonstrated by the findings of the dual staining assay. In silico molecular docking studies showed that eupatilin exhibited binding affinities of −7.3 kcal/mol for BCL-2 (RMSD: 1.000 Å) and −6.6 kcal/mol for CDK6 (RMSD: 0.992 Å), suggesting potential molecular interactions with these key regulatory proteins. Conclusion The findings of this work indicate that eupatilin treatment successfully inhibited growth and triggered apoptosis in breast cancer cells. Consequently, it possesses the potential to serve as an anti-cancer drug candidate for breast cancer therapy.