Active ingredients and molecular targets of Tripterygium wilfordii against colorectal cancer: network pharmacology, molecular docking, molecular dynamics simulations and in vitro evaluation

Abstract

Colorectal cancer (CRC) is one of the common malignant tumors of the gastrointestinal tract, encompassing both colon cancer and rectal cancer. This study explores the therapeutic potential of T. wilfordii in CRC through network pharmacology, molecular docking, and in vitro experiments. Active components of T. wilfordii were screened using oral bioavailability (OB ≥ 30%) and drug-likeness (DL ≥ 0.18) criteria. Protein–protein interaction network analysis, gene ontology functional enrichment, and kyoto encyclopedia of genes and genomes pathway enrichment were performed to identify candidate targets and signaling pathways. Molecular docking and molecular dynamics simulations were used to predict compound–target binding modes and to assess the dynamic stability of selected docked complexes. In vitro experiments, including CCK-8 assay, EGFR kinase activity assay, EGF rescue assay, and Western blot analysis, were conducted to evaluate the anticancer activity of key components and the involvement of EGFR signaling in CRC cell lines (HT29 and HCT116). A total of 51 active compounds were identified from T. wilfordii, with 23 core components selected for further analysis. PPI network analysis identified TP53, AKT1, EGFR, STAT3, and mTOR as central candidate targets, and KEGG enrichment analysis highlighted cancer-related pathways including PI3K/Akt, Wnt/β-catenin, and mTOR. Molecular docking, interpreted with target-specific reference-ligand redocking benchmarks, prioritized several core components, including β-Sitosterol (Lei3), Tryptophenolide (Lei4), Tripterifordin (Lei8), Isoxanthohumol (Lei9), and Stigmasterol (Lei16), as compounds with favorable AutoDock Vina docking scores toward EGFR. MD simulations supported the relative stability of the docked EGFR-Lei4 complex under the simulation conditions. In vitro EGFR kinase activity assay showed that Lei4 directly inhibited recombinant EGFR kinase activity in a concentration-dependent manner, with an IC50 value of 1.38 ± 0.12 μM. In cell-based assays, Lei4 inhibited HT29 and HCT116 cell proliferation in a dose-dependent manner, with IC50 values of 27.98 ± 3.56 μM and 28.0 ± 3.6 μM, respectively. EGF partially reversed Lei4-induced proliferation inhibition, and Western blot analysis showed that Lei4 decreased the phosphorylation levels of EGFR, ERK1/2, and JUN without markedly altering total protein expression. T. wilfordii may exert anti-CRC effects through a multi-component, multi–target, and multi-pathway mechanism. Tryptophenolide (Lei4) showed moderate but reproducible anti-CRC activity and directly inhibited EGFR kinase activity in vitro, supporting EGFR pathway inhibition as one mechanism contributing to its cellular effects. These findings provide a basis for further optimization and mechanistic evaluation of T. wilfordii -derived active compounds in CRC.