Integrating network pharmacology, molecular dynamics, and in vitro assays to unveil the mechanism of costunolide against gastric cancer.

Gastric cancer (GC) stands as a major contributor to global cancer deaths. Due to tumor heterogeneity and drug resistance, current treatments remain unsatisfactory, highlighting the urgent need for novel targeted therapeutics. Costunolide (Cos), a natural sesquiterpene lactone, has shown notable anticancer activity. However, its primary upstream molecular target in GC remains unclear. We integrated network pharmacology (NP), molecular docking, molecular dynamics (MD) simulations, and in vitro assays to investigate the mechanisms of Cos against GC. NP analysis recognized ERBB2 as a core target and suggested that Cos may exert its pharmacological function through the PI3K/AKT and MAPK signaling pathways. Molecular docking showed strong binding between Cos and ERBB2, and MD simulations further supported the stability of the complex. In vitro evaluations demonstrated that Cos exhibits strong anti-proliferative effects against NCI-N87 and HGC-27 cell lines, in addition to stimulating programmed cell death. Western blot analysis revealed regulatory changes in apoptosis-related factors and key components of the ERBB2/PI3K/AKT/MAPK signaling cascades. Rescue experiments confirmed the pivotal role of ERBB2: overexpression of ERBB2 attenuated the effects induced by Cos, whereas knockdown of ERBB2 enhanced its activity. Collectively, these results suggest that Cos promotes programmed cell death in GC through the inhibition of ERBB2 and the subsequent attenuation of its downstream PI3K/AKT and MAPK signaling. This work provides a mechanistic basis for developing Cos as a potential therapeutic solution for GC.