Abstract / Summary
Metabolic endpoint assays enable rapid screening but provide limited information on treatment kinetics, heterogeneity, and recovery. Here, we established a multistep workflow combining MTS-based metabolic screening with electric cell–substrate impedance sensing (ECIS), a label-free cell-based biosensor, to functionally prioritize complex plant extracts in head and neck squamous cell carcinoma (HNSCC) models. Seventeen soluble extracts were screened at 50 µg/mL for 24 h in four HNSCC cell lines and human adipose-derived stem cells. Selected candidates were characterized by real-time impedance monitoring, multifrequency analysis, and model-derived barrier resistance. Extract 16 showed the most favorable metabolic selectivity profile. ECIS resolved no growth-inhibitory effects, sustained impedance suppression, heterogeneous responses, and transient suppression followed by partial recovery. Recovery was incomplete (CAL-33) or absent (Detroit 562); modeled barrier resistance became resolvable late (FaDu, PE/CA-PJ15) or not at all (CAL-33). Comparison with the PI3Kα inhibitor Inavolisib revealed partially overlapping but non-identical metabolic response profiles and no consistent enhancement by combination treatment. Extract 16 was associated with junctional redistribution, F-actin remodeling, and cell line-dependent PARP cleavage, whereas caspase 3/7 activation could not be detected. Integrating metabolic endpoint screening with multiparametric ECIS monitoring provides greater functional resolution and supports prioritizing complex bioactive samples for chemical and mechanistic investigation.