ETHNOPHARMACOLOGICAL RELEVANCE: Baihezhijiegeng is a processed product of Platycodonis radix, and it's effective in the treatment of Chronic Obstructive Pulmonary Disease (COPD). However, the specific mechanism of action has not been reported in the literature.
AIM OF THE STUDY: We attempted to evaluate the phytochemical composition and pharmaco-dynamics of Platycodon grandiflorum (PG) and BJ to clarify the mechanism behind the expectorant effect of BJ.
MATERIALS AND METHODS: We integrated the ultra-high-performance liquid chromatography-linear trap quadrupole orbitrap velos mass spectrometry (UPLC-LTQ Orbitrap MS/MS) and the ultra-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) methods to identify the chemical constituents of PG and BJ. Moreover, correlation and multivariate statistical analyses were utilized to seek the candidate quality markers of PG and BJ. Analysis of effective herbal chemical components using UPLC-Q-TOF-MS/MS and retrieval of COPD disease targets from OMIM, TTD, GeneCard databases. Protein-protein interaction (PPI) and topology analyses were performed using the String database and Cytoscape 3.7.2 software; gene ontology (GO) functional enrichment analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed using the Metescape platform on common targets. Moreover, we used molecular docking to predict the potential mechanism of quality markers for developing anti-COPD activity. Simultaneously, the model of COPD was established by exposing the animals to cigarette smoke combined with a tracheal drip injection of lipopolysaccharide (LPS). Using the ELISA method, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB) to determine tumor-necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and matrix metalloproteinase (MMP)9 levels in serum and IL-4, IL-10, IFN-γ levels, epidermal growth factor receptor (EGFR) and MUC5AC expression in lung tissue of COPD rats to explore the therapeutic effects of PG and BJ on the COPD rat model.
RESULTS: The chemical identification of JG and PG extracts using UPLC-Q-TOF-MS/MS and UPLC-LTQ Orbitrap MS/MS showed 71 compounds, including 47 saponins, 16 phenolic acids, four flavonoids, and four other components. The multivariate statistical analysis showed that seven quality markers were screened. Network pharmacology results showed a role in biological processes such as cellular response to hydrogen peroxide, positive regulation of pri-miRNA transcription from RNA polymerase II promoter, molecular functions such as oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor, bile acid binding and other molecular functions. In COPD rats, histopathological findings depicted that BJ administration could effectively inhibit inflammatory cell infiltration and mucus hypersecretion, and improve the lung pathological status in rats with COPD. Moreover, BJ could significantly decrease TNF-α, IL-1β, IL-6, and matrix metalloproteinase (MMP)9 levels in the serum and interferon (IFN)-γ levels in lung tissues of rats with COPD (p < 0.01), and significantly increase IL-4 and IL-10 levels in their lung tissues (p < 0.01), suggesting its inhibition of the inflammatory response in vivo. Additionally, EGFR and MUC5AC were reduced in the lung tissues of rats with COPD and airway mucus hypersecretion in rats with COPD.
CONCLUSION: This study revealed the material basis of PG and BJ for anti-COPD activity and discovered the quality markers of PG and BJ which could affect the anti-COPD activity. The therapeutic effects of BJ may be attributed to the regulation of the inflammatory mediators and mediation of the EGFR/MUC5AC pathway in rats with COPD.