In Vitro Therapeutic Potential and Morphological Effects of Rosmarinic Acid Derivatives on Triple‐Negative Breast Cancer Cell Line

Abstract Breast cancer remains a global health challenge, necessitating more effective treatments. The demand for novel therapeutics highlights the need for a deeper understanding of drug mechanisms. High‐content screening (HCS) emerges as a tool to investigate drug effects comprehensively. In this study, we investigated the potential of rosmarinic acid (RA) and its ester derivatives in treating the aggressive subtype triple‐negative breast cancer (TNBC). We revealed insights into the effects of RA and ester derivatives on TNBC cell line MDA‐MB‐231, alongside normal mammary epithelial cell line MCF‐10A. RA and RAME exhibited significantly elevated therapeutic index (TI) of 4.03 and 0.97, respectively, compared to their counterparts. HCS analysis unveiled morphological distinctions between MDA‐MB‐231 and MCF‐10A cell lines, shedding light on their differential responses to RA derivatives. PCA results demonstrated the influence of RA esters on organelles, notably Golgi and endoplasmic reticulum. Furthermore, RAME exhibited potential in suppressing invasion and migration ability of MDA‐MB‐231 cell line. A significant increase in Caspase‐3 gene expression levels was observed in RAME‐treated MDA‐MB‐231 cells, whereas BCL‐2 gene expression levels decreased significantly. Our findings highlight the therapeutic potential of RAME in TNBC and emphasize the critical role of HCS in uncovering drug effects.