Identification of anticancer and cardioprotective quality markers in Chuanxiong Rhizoma using a bioassay driven effect-constituent index approach.

Ligusticum Chuanxiong (Chuanxiong Rhizoma) is used in Traditional Chinese medicine (TCM) and has cardioprotective effects. Trastuzumab improves outcomes in HER2-positive breast cancer, but acquired resistance and cardiotoxicity limit its utility. Current quality-control methods rarely integrate composition with functional efficacy, hindering rational standardization. We developed an efficacy-oriented quality-control strategy that couples HPLC profiling with in vitro bioassays. HPLC profiling of 12 commercial batches identified ten common constituents: tetramethylpyrazine, chlorogenic acid, ferulic acid, senkyunolide I, senkyunolide H, 6″-feruloylspinosin, senkyunolide A, n-butylbenzene, ligustilide, and butenylbenzene. All constituents were evaluated by CCK-8 assay to identify those with both cytotoxic activity against a trastuzumab-resistant HER2-positive breast cancer cell line and protective effects against trastuzumab-induced cardiomyocyte injury. We constructed two Effect-Constituent Indexes (ECIJ for cytotoxicity; ECIH for cardioprotection) by weighting abundances by measured bioactivities. Both indices correlated with experimentally determined potency (ECIJ vs 1/IC50: rJ = 0.727, **P < 0.01; ECIH vs 1/EC50: rH = 0.592, *P < 0.05) and discriminated batches better than single markers. Batch S10 exhibited the strongest dual efficacy (IC50 = 0.6553 mg/mL; EC50 = 0.00288 mg/mL). Molecular docking indicated that bioactive constituents may modulate ferroptosis via interactions with SLC7A11 and FSP1. The integrated ECI framework offers an efficacy-driven quality control approach for Chuanxiong Rhizoma and supports its dual application to enhance antitumor activity while mitigating trastuzumab-induced cardiotoxicity.