Biological Effects of Umbelliferone in MCF-7 Breast Cancer Cells: Integrated In Vitro and Computational Analyses

Background/Objectives: Breast cancer remains a leading cause of cancer-related mortality among women, highlighting the need for further investigation of bioactive compounds with selective effects on cancer cells. This study evaluated the biological effects of the natural coumarin derivative umbelliferone in MCF-7 breast cancer cells using integrated in silico and in vitro approaches. Methods: Molecular docking predicted interactions with AKT1, mTOR, PI3Kα, and Caspase-7, while molecular dynamics simulations and MM/PBSA calculations provided further information on interactions with AKT1 and mTOR. Results: Umbelliferone reduced MCF-7 cell viability in a concentration-dependent manner, with an IC50 of 492 µM after 24 h, whereas 50% viability was not reached in BJ normal fibroblasts up to 1400 µM, corresponding to an IC50 > 1400 µM and a selectivity index > 2.85. Annexin V-FITC/PI analysis showed increased apoptotic populations, with total apoptosis significantly increased at 800 µM. Colony formation analysis further indicated reduced clonogenic capacity. At 400 µM, umbelliferone significantly increased relative Caspase-3/7 and Caspase-9 activities to 1.873 ± 0.635 and 2.483 ± 0.092, respectively, whereas neither activity was significantly increased at 800 µM. In silico ADME analysis predicted properties compatible with commonly used drug-likeness criteria. Conclusions: Collectively, the findings demonstrate effects of umbelliferone on cell viability, apoptosis, clonogenic capacity, and caspase activity in MCF-7 cells, with comparatively lower cytotoxicity toward normal fibroblasts. Computational findings remain hypothesis-generating and do not establish direct target engagement or pathway inhibition. Further mechanistic and in vivo studies are required to determine the biological and pharmacological relevance of these findings.