Exploring the mechanism of Shexiang Tongxin dropping pill in the treatment of microvascular angina through network pharmacology and molecular docking

Background: Microvascular angina (MVA) is a group of clinical manifestations of angina pectoris or angina-like chest pain, positive exercise test, and exclusion of epicardial coronary artery spasm, wherein coronary angiography (CAG) does not present obvious epicardial vascular stenosis. Shexiang Tongxin dropping pill (STDP) has the effect of benefiting the Qi and opening the blood vessels, activating blood circulation, and resolving blood stasis. We explored the mechanism of STDP against MVA by network pharmacology and molecular docking. Methods: Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), literature search, SwissTargetPrediction database, and high-throughput experiment- and reference-guided database of traditional Chinese medicine (HERB) were applied to identify the active ingredients and targets of STDP. The MVA targets were searched in the databases of GeneCards, Pharmacogenetics and Pharmacogenomics Knowledge Base (PharmGKB), DisGeNET, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Database (TTD). The common targets of STDP and MVA were screened. The software RStudio 4.1.3 was used to analyze the enrichment of these targets using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Protein-protein interaction (PPI) network analysis of the common targets was performed using the Search Tool for the Retrieval of Interacting Genes/Genomes (STRING) database. The cytoHubba plug-in of Cytoscape 3.9.1 software was employed to analyze the PPI network and obtain the core targets. Molecular docking was performed to verify the relationship between the core compounds and proteins with AutoDock Tools 1.5.7 and Pymol 2.4.0. Results: We identified 93 effective components of STDP, 310 potential targets, 981 MVA targets, and 138 intersectional targets. The potential anti-MVA mechanism of STDP may involve the advanced glycation end products/receptor for advanced glycation end products (AGE-RAGE) signaling pathway in diabetic complications; lipids and atherosclerosis; fluid shear stress; atherosclerosis; the tumor necrosis factor (TNF), interleukin (IL)-17, hypoxia-inducible factor (HIF)-1, and C-type lectin receptor signaling pathways. Further, STDP mainly acts on its targets IL-6, AKT1, STAT3, JUN, and IL-1 beta to against MVA. Conclusions: The STDP may exert its therapeutic effects through processes, such as anti-inflammation, promotion of smooth muscle cell proliferation and differentiation, lipid metabolism, immunomodulation, and regulation of cellular autophagy.