Early-stage toxicological assessment is crucial for identifying chemical compounds with the potential to cause adverse cellular effects. In vitro cytotoxicity assays are commonly used as initial screening tools to compare how cells respond to structurally related compounds and to support hazard evaluation. In this study, the cytotoxicity of two organic parent compounds and their corresponding vanadium (III) complexes was examined to determine the impact of metal coordination on cellular viability. Cytotoxicity was evaluated using the MTT assay after 48 hours of exposure over a specified concentration range. Comparative concentration–response patterns were examined to detect differences in cellular sensitivity between parent ligands and their metal complexes. Additionally, molecular docking was conducted against the human ATP-binding cassette efflux transporter ABCG2 (breast cancer resistance protein, BCRP) as a complementary in silico method to investigate potential interactions relevant to xenobiotic disposition. The results revealed distinct cytotoxicity profiles between the parent compounds and their vanadium (III) complexes, indicating that metal coordination influences cellular responses under identical experimental conditions. Docking analysis suggested that the parent ligands can occupy the inhibitor-defined transmembrane cavity of ABCG2, supporting a mechanistically plausible role of transporter interaction in causing variability in apparent cytotoxicity, without implying functional inhibition. Overall, this combined in vitro and in silico screening-level assessment underscores the importance of considering metal coordination in toxicological evaluation and supports the use of complementary computational methods to contextualize cytotoxicity data in early hazard characterization of metal–organic systems.