Using network pharmacology and molecular docking verification to explore the mechanism of ursolic acid in the treatment of osteoporosis

Abstract

Whether ursolic acid is an effective drug in treatment of osteoporosis (OP) and how it exhibit activity effect on OP is unclear. To investigated the potential molecular mechanism of ursolic acid in the treatment of OP and figured out its possible mechanism is necessary. The target genes of ursolic acid were screened by using the database of traditional chinese medicine systems pharmacology, PubMed database and UniProt database. OP-related target genes were searched by GeneCards database, and utilized online mapping tool to obtain common target genes of component-disease. String database was used to construct a protein-protein interaction (PPI) network of component-disease common target genes and perform topological analysis to screen core target genes. DAVID database was performed gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for component-disease shared target genes. Using the core target protein as the receptor and ursolic acid as the ligand, the molecular docking was performed using AutoDockVina 1.1.2 software. A total of 52 ursolic acid-related target genes and 4657 OP-related target genes were excavated, with a total of collective 43 target genes. The above-mentioned PPI network with shared target genes contains 43 nodes and 510 edges, with an average node degree value of 23.32. A total of 24 core target genes were obtained, mainly including tumor protein p53 (TP53), vascular endothelial growth factor A (VEGFA), interleukin-6 (IL6), tumor necrosis factor (TNF), caspase3 (CASP3), matrix metallo protein (MMP9), transcription factor AP-1 (JUN), activator of transcription 3 (STAT3), mitogen-activated protein kinase 8 (MAPK8), and prostaglandin endoperoxidase 2 (PTGS2), respectively. According to KEGG enrichment analysis, there are 126 treatment of OP signaling pathway were enriched. GO enrichment analysis revealed that 313 biological processes were identified. The molecular docking result showed that the binding energies were all lower than −5 kcal/mol, indicating strong binding activity to the protein by the 6 core target gene. The therapeutic effect of ursolic acid on OP may be achieved by regulating TP53, JUN, IL6, VEGFA, CASP3, and MAPK8 genes, respectively. It exhibits possible biological function in the treatment of OP mainly involve positive regulation of apoptotic process, response to drug, incytoplasm, cytosol, protein binding, identical protein binding. Its mechanism may related to multiple therapeutic targets and signaling pathways such as cancer pathway, hepatitis B, and TNF signaling pathway.