Background
Polygonum cuspidatum
is a Chinese medicine commonly used to treat phlegm-heat asthma. However, its anti-asthmatic active ingredients and mechanism are still unknown. The aim of this study was to predict the active ingredients and pathways of
Polygonum cuspidatum
and to further explore the potential molecular mechanism in asthma by using network pharmacology.
Methods
The active ingredients and their targets related to
Polygonum cuspidatum
were seeked out with the TCM systematic pharmacology analysis platform (TCMSP), and the ingredient-target network was constructed. The GeneCards, DrugBank and OMIM databases were used to collect and screen asthma targets, and then the drug-target-disease interaction network was constructed with Cytoscape software. A target protein-protein interaction (PPI) network was constructed using the STRING database to screen key targets. Finally, GO and KEGG analyses were used to identify biological processes and signaling pathways. The anti-asthmatic effects of
Polygonum cuspidatum
and its active ingredients were tested in vitro for regulating airway smooth muscle (ASM) cells proliferation and MUC5AC expression, two main symptoms of asthma, by using Real-time PCR, Western blotting, CCK-8 assays and annexin V-FITC staining.
Results
Twelve active ingredients in
Polygonum cuspidatum
and 479 related target proteins were screened in the relevant databases. Among these target proteins, 191 genes had been found to be differentially expressed in asthma. PPI network analysis and KEGG pathway enrichment analysis predicted that the
Polygonum cuspidatum
could regulate the AKT, MAPK and apoptosis signaling pathways. Consistently, further in vitro experiments demonstrated that
Polygonum cuspidatum
and resveratrol (one active ingredient of
Polygonum cuspidatum
) were shown to inhibit ASM cells proliferation and promoted apoptosis of ASM cells. Furthermore,
Polygonum cuspidatum
and resveratrol inhibited PDGF-induced AKT/mTOR activation in ASM cells. In addition, Polygonum cuspidatum decreased H
2
O
2
induced MUC5AC overexpression in airway epithelial NCI-H292 cells.
Conclusion
Polygonum cuspidatum could alleviate the symptoms of asthma including ASM cells proliferation and MUC5AC expression through the mechanisms predicted by network pharmacology, which provides a basis for further understanding of
Polygonum cuspidatum
in the treatment of asthma.