Anti-inflammatory mechanism of rhein in treating asthma based on network pharmacology

Objective: To predict the anti-inflammatory targets and related pathways of rhein in the treatment of asthma by using network pharmacology, and to further explore its potential mechanism in asthma.

Methods: The corresponding targets of rhein were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and the rhein-target network was constructed with Cytoscape 3.7.1 software. The Genbank and Drugbank databases were used to collect and screen asthma targets, and the rhein-target-disease interaction network was constructed. A target protein-protein interaction (PPI) network was constructed using the STRING database to screen key targets. Finally, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was used to identify biological processes and signaling pathways. The anti-asthmatic effects of rhein were tested in vitro, and the expression levels of proteins in the mitogen-activated protein kinase/nuclear factor kappa-B (MAPK/ NF-κB) signaling pathway were assessed by western blot analysis.

Results: Altogether, 83 targets of rhein were screened in the relevant databases, 989 targets of asthma were obtained in the National Center for Biotechnology Information (NCBI) GENE Database. PPI network analysis and KEGG pathway enrichment analysis predicted that rhein could regulate the epidermal active growth factor receptor (EGFR), mitogen-activated protein kinase 14 (MAPK14), tumour necrosis factor receptor superfamily member 1A (TNFRSF1A), receptor tyrosine-protein kinase erbB-2 (ERBB2), and other signaling pathways. Furthermore, we selected the MAPK signaling pathway to determine the anti-inflammatory effects of rhein. Consistently, further experiments demonstrated that rhein was shown to inhibit HBE cells inflammation.

Conclusion: The anti-inflammatory mechanism of rhein in the treatment of asthma may be related to EGFR, MAPK14, TNFRSF1A and ERBB2 as well as their signaling pathways. To prevent the exacerbation of asthma, instead of targeting a single pathway or a single target, all these targets and their signaling pathways should be controlled holistically. Rhein may alleviate the inflammation of asthma by inhibiting the MAPK/NF-κB pathway.