The mechanism and candidate compounds of aged citrus peel (chenpi) preventing chronic obstructive pulmonary disease and its progression to lung cancer

Background: Chronic obstructive pulmonary disease (COPD) is an important risk factor for developing lung cancer. Aged citrus peel (chenpi) has been used as a dietary supplement for respiratory diseases in China. Objective: To explore the mechanism and candidate compounds of chenpi preventing COPD and its progression to lung cancer. Methods: The active components and potential targets of chenpi were retrieved from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. Disease-associated targets of COPD and lung cancer were collected in the Gene Cards and TTD database. The component-target network and PPI network were constructed using the Cytoscape 3.8.0 software. David database was used for GO and KEGG enrichment analysis. The main active components were verified by using the autodock Vina 1.1.2 software. Mouse lung cancer with COPD was induced by cigarette smoking (CS) combined with urethane injection to confirm preventing the effect of hesperetin (the candidate compound of chenpi) on COPD progression to lung cancer and its underlying mechanisms. Results: The network analysis revealed that the key active components of chenpi (nobiletin, naringenin, hesperetin) regulate five core targets (AKT1, TP53, IL6, VEGFA, MMP9). In addition, 103 potential pathways of chenpi were identified. Chenpi can prevent COPD and its progression to lung cancer by getting involved in the PI3K-Akt signaling pathway and MAPK signaling pathway. Molecular docking indicated that hesperetin had better binding activity for core targets. In mouse lung cancer with COPD, treatment with hesperetin dose-dependently improved not only lung tissue injury in COPD but also carcinoma lesions in lung cancer. Meanwhile, hesperetin could suppress the protein expression of AKT1, IL6, VEGFA, MMP9 and up-regulate the protein expression of TP53, and thus reduced the risk of COPD progression to lung cancer. Conclusion: Hesperetin is a candidate compound of chenpi that helps in preventing COPD and its progression to lung cancer by regulating AKT1, IL6, VEGFA, MMP9 and TP53.