[Mechanism of osthole against colorectal cancer based on network pharmacology, molecular docking, and experimental validation]

Through in vitro and in vivo experiments, combined with network pharmacology and molecular docking techniques, this study investigated the mechanism of action of osthole in the treatment of colorectal cancer(CRC). The relevant targets of osthole and CRC were retrieved from the SwissTargetPrediction and SuperPred in drug databases, as well as GeneCards and OMIM in disease databases. Protein-protein interaction(PPI) networks were constructed using the STRING database and Cytoscape 3.8.0 software, and core targets were screened. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were performed on common targets. Molecular docking validation of core targets with osthole was conducted using AutoDock Vina software. HCT116 cells were treated with different concentrations of osthole, and cell proliferation was detected using the CCK-8 assay and the clonogenic assay. Cell migration ability was assessed using Transwell assay. Western blot and RT-qPCR were performed to detect the expression of caspase-3(CASP3), hypoxia-inducible factor 1 alpha(HIF1A), nuclear factor kappa B subunit 1(NFKB1), glycogen synthase kinase-3 beta(GSK3B), phosphorylated-GSK3B(p-GSK3B), protein kinase B(Akt), phosphorylated-Akt(p-Akt), mammalian target of rapamycin(mTOR), and phosphorylated-mTOR(p-mTOR). A subcutaneous tumor model of HCT116 cells in nude mice was established, and the mice were randomly divided into the model group, low-dose osthole group(20 mg·kg~(-1)), medium-dose osthole group(40 mg·kg~(-1)), and high-dose osthole group(60 mg·kg~(-1)). After 18 days of administration, the growth of tumor xenografts was observed, and the size and weight of tumors were measured after excision. Hematoxylin-eosin(HE) staining was performed to observe the histological changes in tumors in each group. Network pharmacology analysis revealed that osthole treatment of CRC mainly involved 106 treatment targets and 113 treatment pathways, with key pathways including the PI3K/Akt signaling pathway and MAPK signaling pathway. Molecular docking results showed a strong correlation between osthole and core targets. In vitro studies demonstrated that osthole significantly inhibited the proliferation and migration ability of HCT116 cells. Western blot and RT-qPCR experiments showed that compared to those in the model group, the expression of NFKB1, HIF1A, p-Akt, p-mTOR, and GSK3B in the osthole-treated group was significantly decreased, while the expression of CASP3 and p-GSK3B(Ser9) was significantly increased. In vivo studies showed that compared to the model group, osthole-fed animals significantly reduced tumor weight and volume, inhibited tumor growth, and promoted tumor apoptosis, and the results showed a dose-dependent trend. The study suggested that osthole could inhibit the proliferation and migration of HCT116 cells in CRC, and its mechanism may be related to the regulation of the PI3K/Akt signaling pathway and the expression of core targets.