Sholeh Javadi; Somayeh Farahmand; Helia Bayat; Reza HajiHosseini; Sima Nasri
Abstract
Triple-negative breast cancer (TNBC) lacks targetable receptors, rendering conventional chemotherapy the sole standard of care despite its associated toxicity and acquired resistance. The constitutively activated NF-κB and STAT3 signaling axes represent mechanistically interdependent oncogenic ...
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Triple-negative breast cancer (TNBC) lacks targetable receptors, rendering conventional chemotherapy the sole standard of care despite its associated toxicity and acquired resistance. The constitutively activated NF-κB and STAT3 signaling axes represent mechanistically interdependent oncogenic drivers in TNBC, making their simultaneous inhibition a compelling therapeutic strategy. β-Sitosterol, the predominant phytosterol of Allium cepa seeds, has demonstrated broad antiproliferative properties; however, its capacity for dual-target engagement against NFKB1 and STAT3 has not been systematically characterized. GC–MS profiling of A. cepa seed oil identified β-sitosterol as the principal constituent (80.45%). Computational ADMET analysis, Human Protein Atlas-based immunocytochemical target validation, and Auto Dock Vina molecular docking against NFKB1 (PDB: 5AX3) and STAT3 (PDB: 7LET) were performed. Anticancer activity was evaluated in MDA-MB-231 cells via MTT assay, with apoptotic mechanism characterized by Annexin V-FITC/PI flow cytometry. β-Sitosterol demonstrated favorable drug-likeness with predicted mitochondrial localization and absence of mutagenicity. Docking yielded binding energies of −7.0 and −6.7 kcal/mol for STAT3 and NFKB1, respectively, driven by hydrophobic interactions. MTT assay revealed concentration-dependent cytotoxicity (IC₅₀ = 39.56 µM; 72 h; F = 113.8, p < 0.0001). Flow cytometry confirmed significant induction of early (30.7 ± 2.5%) and late apoptosis (20.3 ± 4.4%) versus negligible baseline levels in controls. β-Sitosterol exhibits dual computational binding affinity for NFKB1 and STAT3 alongside potent pro-apoptotic activity in TNBC cells, establishing a mechanistic foundation for its further translational development.
