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Introduction and Objectives: The failure of targeted chemotherapy especially in triple negative breast cancer (TNBC) patients has been correlated with the overexpression of the mesenchymalepithelial transition factor (c-Met) receptor. Thus, the hepatocyte growth factor (HGF)/c-Met signaling axis has gained considerable attention as a valid molecular target for breast cancer therapy. No reports addressed the potential anticancer action of Ziziphus lotus, an edible typical Tunisian plant known by locals for its numerous therapeutic virtues. In the present study, we investigated for the first time the anti-tumor activity of Z. lotus leaf extract against human breast cancer cell lines. Material and Methods: Bioguided fractionation of leaves ethanolic extract was performed using different chromatographic techniques and MTT assay. The structures of three compounds were elucidated by NMR spectroscopy analysis and high-resolution mass spectrometry. The cell free Z'-LYTE kinase assay and in vitro biological screening on human breast cancer cells using cell viability, adhesion, migration, western blotting and in silico docking experiments were carried out to investigate the anti-tumoral activity of the purified lead compound and its mechanism of action. Tumor growth was evaluated in vivo using nude mice breast cancer xenograft model. Results: This study reports the discovery of three purified photosensitizers as the potent antiproliferative compounds against the human breast cancer cells MDA-MB-231 and MCF-7. Compound 3 exerted the most light-independent antitumor effect against the metastatic human MDA-MB-231 cells. In silico, this compound showed excellent binding mode and score at the kinase domain of multiple c-Met crystal structures. It potently inhibited the kinase domain phosphorylation of wild and mutant c-Met. Compound (3) inhibited HGF-induced downstream c-Met-dependent cell proliferation, survival, adhesion and migration through RAF/MEK/ERK and PI3K/PTEN/AKT signaling pathways modulation, ROS generation and activation of JNK and p38 pathways. Interestingly, this compound impaired the ability of MDA-MB-231 cells to adhere at different extracellular matrix proteins by reducing the HGF-induced expression of integrins av, ß3, a2 and ß1. Moreover, compound (3) exhibited potent anti-migratory properties through impacting the expression levels of E-cadherin, vimentin, -catenin, FAK, Brk, Rac, and Src proteins. Importantly, treatment with this compound significantly inhibited the MDA-MB-231 tumor growth in orthotopic athymic mouse xenograft model. Conclusion: Compound (3) is a novel c-Met inhibitory lead with promise to control c-Met/HGFdependent breast malignancies. [ABSTRACT FROM AUTHOR]