Mechanisms of pancreatic tumor suppression mediated by Xiang-lian pill: An integrated in silico exploration and experimental validation

Ethnopharmacological relevance: Xiang-lian pill, consisting of Coptis chinensis Franch. coprocessed with Tetradium ruticarpum (A.Juss.) T.G.Hartley (Yu-huang-lian) and Aucklandia lappa DC. (Mu-xiang), is traditionally used to relieve fever, abdominal pain, and gastrointestinal inflammatory symptoms observed in patients with malignancies of the gastrointestinal tract. Each of the three herbs contained in Xiang-lian pill has been indicated to have Anticancer effects on a variety of cancers, but its effects on pancreatic Cancer remain unexplored. The main extracts of these herbs have anti-pancreatic Cancer effects, but the comprehensive mechanism of this compound prescription of Xiang-lian pill in pancreatic Cancer remains to be revealed.

Aim of the study: To explore the main active ingredients, potential anti-pancreatic Cancer targets, and related mechanisms of the Xiang-lian pill and to determine its therapeutic value in vivo.

Materials and methods: Network pharmacology and bioinformatics analysis were applied to screen the potential effective ingredients and key targets. Liquid/gas-mass spectrometry was performed for ingredients validation. Molecular docking and the cellular thermal shift assay were performed to test the binding efficiency between ingredients and targets. A murine pancreatic Cancer model was established and administered different doses of the Xiang-lian pill. Hematoxylin-eosin staining was used for histopathological observation. Immunohistochemistry and immunoblotting were conducted for target validation. In vitro studies (cell viability and clonogenicity assays) were conducted to investigate the impact of three main ingredients in Xiang-lian pill on pancreatic Cancer cells. PTGS2 overexpression was performed to reversely confirm the antitumor mechanisms of rutaecarpine as a specific PTGS2 inhibitor.

Results: Xiang-lian pill suppressed pancreatic Cancer growth in the dose range of 0.78-2.34g/kg with no significant toxicity. Sixteen potentially active ingredients and 26 corresponding therapeutic targets for pancreatic Cancer were identified. PTGS2, PTGS1, KCNH2, PRSS1, and HSP90AA1 were the top 5 significant genes targeted by the Xiang-lian pill. Evodiamine, rutaecarpine and stigmasterol bound to PTGS2 and PTGS1 with different affinities and inhibited pancreatic Cancer cell proliferation. The PTGS2-associated metabolic pathway MEK/ERK was downregulated by rutaecarpine in vitro and the Xiang-lian pill in vivo.

Conclusions: Xiang-lian pill mainly regulates inflammation, Apoptosis, metastasis, and metabolism to exert an antitumor effect. The main active ingredients in Xiang-lian pill exhibit antitumor roles through directly binding to key targets in pancreatic Cancer. PTGS2 mediated MEK/ERK inhibition by rutaecarpine represents a key therapeutic mechanism of Xiang-lian pill.