OBJECTIVE To elucidate the pharmacological effects and mechanisms of costunolide(COS), the active component of Inula racemosa Hook.f., through network pharmacology analysis combined with experimental validation.

METHODS Network pharmacology approach was adopted to screen the potential targets of COS from 5 databases(PharmMapper, SwissTargetPrediction, TargetNet, CTD, and Super-PRED). GC-related targets were retrieved from GeneCards and OMIM databases. GO and KEGG enrichment analyses were performed using Metascape database. Molecular docking of COS with target proteins was conducted using AutoDock Vina 1.5.6. The proliferative and migratory effects of COS on GC cells were evaluated by CCK-8 assay, colony formation assay, and wound healing assay. Cell apoptosis was assessed by Hoechst 33342 staining, Annexin V-FITC/PI flow cytometry, and JC-1 mitochondrial membrane potential assay. The underlying mechanisms were validated by qPCR and Western blotting.

RESULTS A total of 100 potential targets were obtained by network pharmacology screening, with EGFR, CASP3, TNF, HSP90AA1, and ESR1 as the top 5 core targets, and the PI3K/AKT signaling pathway was the core pathway. In vitro experimental results showed that COS could inhibite the proliferation of the GC cell lines AGS, HGC-27, and NCI-N87, while inducing apoptosis in HGC-27 cells. qPCR and Western blotting results showed that COS could reduce the mRNA and protein expression levels of p-PI3K and p-AKT, and induce apoptosis in HGC-27 cells by up-regulating BAX, downregulating Bcl-2 and activating Caspase-3.

CONCLUSION COS exerts anti-tumor effects by modulating the PI3K/AKT signaling pathway, inhibiting GC cell proliferation and promoting its apoptosis.