In recent years, great progress has been made in treating COPD with TCM. The application of TCM can enhance clinical symptoms of COPD patients, decrease acute exacerbations, improve lung function, and reduce inflammatory responses[34]. According to TCM, the main pathogenesis of COPD is the deficiency of lung, spleen and kidney and the mixture of deficiency and excess[35]. SMI is a herbal injection extracted from Red ginseng and Ophiopogon japonicus, commonly used for treating qi-yin deficiency. Studies have shown that SMI possesses anti-inflammatory and antioxidant properties, which can alleviate pulmonary inflammation and oxidative stress[36] [37, 38]. However, the effective components of SMI in treating COPD, as well as its specific targets and signaling pathways, remain unclear. Therefore, it is essential to elucidate the pharmacological mechanisms of SMI in COPD using network pharmacology.
In this study, screening and topological analysis of relevant databases revealed 28 potential components of SMI that may play crucial roles in COPD treatment. These include orchinol, jasmololone, ophiopogonanone B, N-trans-feruloyltyramine, ophiopogonanone A, ruscogenin, (20R)-protopanaxatriol, oleanolic acid, (20S)-protopanaxatriol and stigmasterol, among others. While the pathogenesis of COPD remains incompletely understood, it is generally associated with inflammation, oxidative stress, protease/anti-protease imbalance, and decreased immunity[39]. Ophiopogonanone A and Ophiopogonanone B belong to a class of homoisoflavonoids, an uncommon flavonoid group primarily sourced from Ophiopogon japonicus. These compounds possess oxygen free radical scavenging, anti-oxidative, anti-inflammatory, and myocardial protective properties[40, 41]. 20(S)-protopanaxatriol has been shown to inhibit extracellular matrix deposition and reduce the levels of proinflammatory cytokine[42]. Ruscogenin exerts a protective effect on lung injury due to its anti-inflammatory and anti-thrombotic activities[43]. Furthermore, n-trans-feruloyltyramine demonstrates potent antioxidant capabilities, significantly protecting against ROS-induced oxidative damage by improving cell viability, restoring cell morphology, and maintaining mitochondrial integrity[44]. Additionally, stigmasterol has been documented to have immunomodulatory effects with substantial therapeutic potential in murine experiments[45]. These findings suggest that SMI may employ multiple effective molecular compounds acting through diverse mechanisms in the treatment of COPD.
A total of 341 common targets between SMI and COPD were predicted, leading to the construction of the PPI network. The hub genes of SMI in treating COPD were identified as STAT3, SRC, EGFR, HSP90AA1, AKT1, IL6, TNF, BCL2, JUN, and CCND1. The expression and activation of STAT3 are involved in the inflammatory and fibrotic responses associated with COPD development[46, 47]. Additionally, the SRC/MAPK pathway has been studied for its crucial role in COPD progression[48]. EGFR plays a pivotal role in airway inflammation, showing higher expression levels in COPD patients compared to smokers with normal lung function. Activated EGFR contributes to the proliferation of airway epithelial goblet cells and increased mucus production. Studies have reported that EGFR levels in the small airways of COPD patients are associated with decrease in airway functionality[49]. Literature reports indicate that the pathogenesis of squamous cell lung carcinoma in COPD patients is regulated by HSP90AA1[50]. Moreover, Akt1 regulates cell proliferation and apoptosis, as well as the release of inflammatory factors and activation of inflammatory cells, playing a crucial role in the development of COPD[51, 52].
As previously mentioned, the targets mainly focus on inflammation and cancer. The KEGG enrichment analysis identified significant pathways such as pathway in cancer, PI3K-Akt signaling pathway, AGE-RAGE signaling pathway in diabetic complications and EGFR tyrosine kinase inhibitor resistance. Airway wall remodeling and mucus hypersecretion are key pathological features of COPD, marked by structural changes in the airway wall, luminal stenosis, and restricted airflow[53]. The PI3K/Akt signaling pathway is significantly involved in the pathogenesis of COPD, influencing the activation of inflammatory cells, secretion of inflammatory mediators, and airway remodeling[54]. Studies have shown heightened activation of the PI3K/Akt pathway in airway epithelial cells of COPD patients compared to those without the condition, suggesting a potential role in airway remodeling and fibrosis via NF-κB or mTOR signaling pathways[55, 56]. Furthermore, abnormal PI3K signaling adversely affects the function of airway epithelial cells and impairs alveolar immune cells, leading to excessive immune responses[57]. This aberrant immune response induces chronic inflammation, contributing to COPD development[58]. Therefore, SMI may regulate downstream inflammatory cytokines by attenuating PI3K/AKT signaling. Chronic inflammation elevates levels of EGFR and its ligands. A positive correlation exists between the expression and activation of EGFR and the proliferation of airway epithelial goblet cells and mucus production[59]. Studies have indicated that COPD patients exhibit higher levels of EGFR expression compared to smokers with normal lung function, suggesting a link between COPD and EGFR overexpression. Research suggests that EGFR levels in the small airways of patients with COPD are associated with decreased airway function[39]. COPD is reported to be associated with cancer development and can increase the risk of lung cancer[60].
Molecular docking is a key method for screening active ingredients and calculating their binding affinity to target proteins, which determines binding stability[61]. Typically, affinity is represented by the binding score in molecular docking; the lower the affinity, the more stable the binding to the target protein. In the study, molecular docking results indicated that EGFR, AKT1 and HSP90AA1 showed excellent docking scores with various components, all below − 6.0 kcal·mol− 1. Notably, AKT1 exhibited the strongest interaction with stigmasterol, evidenced by its lowest docking score of − 10.8 kcal·mol− 1. These molecular docking findings demonstrate favorable binding activity between core components of SMI and key target proteins. Consequently, these core components may act as pharmacodynamic agents within SMI, modulating key targets for COPD treatment.
Comorbidities of COPD significantly impact the quality of life, exacerbation frequency, and survival of COPD patients, presenting greater management challenges[62]. Additionally, addressing comorbidities has long been recognized as essential to COPD management. Based on the study findings, the mechanism of SMI in treating COPD includes anti-cancer and anti-inflammatory effects, as well as modulation of various disease pathways such as atherosclerosis and diabetic complications. These findings suggest that SMI could offer extensive and pleiotropic pharmacological activities against COPD comorbidities, aligning with the holistic concept of TCM and the principle of “homotherapy for heteropathy”. Furthermore, this highlights an advantage of TCM in managing COPD.
This present study preliminarily elucidated the molecular mechanism of SMI in treating COPD using network pharmacology and molecular docking. However, certain limitations exist in this study. Firstly, the collection of bioactive components and targets from currently available resources may not be comprehensive. Secondly, confidence is limited due to a lack of further experimental verification. In the future, efforts will be made to validate the therapeutic mechanism of SMI at both cellular and animal model levels.