ObjectiveTo explore the pharmacological mechanism of active saponin compounds of Tuchao Baibiandouren (Lablab Semen Album fried with earth, TCBBDR) in treating type 2 diabetes (T2DM) using UHPLC-Q-Exactive Orbitrap MS and network pharmacology.

MethodsUHPLC-Q-Exactive Orbitrap MS was used for a qualitative analysis of saponin compounds in TCBBDR. PharmMapper and CTD were used to screen drug active compounds and disease targets, and an active compound-target network was constructed via Cytoscape 3.8.0. Molecular docking was applied with the drug active compounds and key targets using AutoDock Vina 1.1.2, and a trajectory for the molecular dynamics simulation was completed by GROMACS 2019-3.

ResultsSixteen saponin compounds were identified from TCBBDR, along with 292 saponin compoud targets and 792 T2DM targets. Through Venn analysis of target saponin constituents and T2DM related targets, a total of 91 intersection targets were screened out in the treatment of T2DM with saponin. The mean values of degree, betweenness centrality and closeness centrality were taken as the thresholds to screen out 22 key genes, among which 4 key proteins namely MAPK1, IGF1 EGFR, PIK3R1 were selected in the top 10 key genes. On this basis, the saponin active constituent-target-signaling pathway network was established. The Gene Ontology (GO) enrichment analysis showed that the related biological modules included activity of steroid hormone receptor, steroid binding, and insulin receptor binding, etc.; the related signaling pathways were EGFR, PI3K-Akt and MAPK, etc.; regulating signaling pathways like MAPK could induce the proliferation, inhibition and apoptosis of pancreatic β cells, increase the quantity of pancreatic β cells, improve the functions of pancreatic β cells and stimulate the insulin secretion. Docking experiment analysis showed that all selected saponin compounds could enter the active sites of targets and form 3 – 14 hydrogen bonds with residues of the active sites. Moreover, van der Waals forces were present between chemical compounds and active sites. By combining the docking binding energy, we determined that the chemical compounds showed strong binding energy to the targets.

ConclusionTCBBDR exerts therapeutic effects on diabetes through multi-compound and multi-target collaboration. Specifically, saponin components mediate pathways including inflammatory reaction and signal transduction to treat T2DM by regulating several key proteins that interact with EGFR and a series of signaling pathways related to disease development.