Identification of cytotoxic constituents from Siegesbeckiae Herba and network pharmacology prediction of their anti-pancreatic cancer mechanisms.

Pancreatic cancer remains a challenging malignancy with limited treatment options. This study aimed to isolate bioactive compounds from Siegesbeckiae Herba and explore their potential mechanisms against pancreatic cancer through network pharmacology and molecular docking. Twenty compounds, including one new compound, were isolated via chromatographic methods and structurally identified by NMR and mass spectrometry. Cytotoxicity of these compounds was evaluated against the human pancreatic cancer cell line PANC-1 using the CCK-8 assay. Two flavonoid constituents, compound 16 (8, 3’-dihydroxy-3, 7, 4’-trimethoxy-6-O-β-D-glucopyranosyl) and compound 17 (quercetin-3-methyl ether), exhibited cytotoxicity, with compound 16 showing the most potent activity (IC50 = 4.48 ± 0.74 µg/mL). Network pharmacology analysis identified 182 potential targets for these compounds, including key targets such as AKT1, PIK3CA, SRC, and HRAS etc. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated enrichment of critical pathways such as PI3K-Akt, Ras, and HIF-1 signaling, which regulate cell proliferation, migration, inflammation, and apoptosis. Molecular docking confirmed strong interactions between compounds 16 and 17 and key pancreatic cancer targets, yet the two flavonoids occupied distinct active pockets. Notably, compound 16 displayed stronger binding affinities (<-7.8 kcal/mol) toward top-ranked targets including HRAS, PIK3CB, PIK3CA, and HSP90AA1. Our results suggest flavonoids from Siegesbeckiae Herba, especially compound 16, as promising candidates for pancreatic cancer treatment, warranting further pharmacological investigation.