Study on Anti-osteoporosis Substance and Mechanism of Action of Spatholobi Caulis Based on Network Pharmacology and Molecular Docking

Objective: To investigate the anti-osteoporotic substances and mechanism of action of the Chinese herbal medicine Spatholobi Caulis. Methods: The active ingredients were acquired with TCMSP, and the targets were obtained with PharmMapper. The common targets were used for the construction of an “ingredient-target” network by Cytoscape 3.7.2, ClueGo and KEGG enrichment analysis were carried out to determine the key pathway of the anti-osteoporosis effect of Spatholobi Caulis. The betweenness, closeness and subnetwork centrality of the nodes were calculated by the CytoNCA. The first 10% nodes of the three indicators were overlaid to screen the key targets for molecular docking analysis. Results: Fourteen active ingredients of Spatholobi Caulis were screened out, involving 221 osteoporotic targets. Its biological target network (456 nodes, 5723 edges) and KEGG pathway network (124 nodes, 365 edges) were obtained by using ClueGo. Two key proteins, SRC and CTSK, were comprehensively screened out by combining the three indicators of the CytoNCA. The results of molecular docking showed that the average binding energy of components JXT-13 and JXT-06 of Spatholobi Caulis to SRC and CTSK were −6.32 and −5.47 kcal/mol, respectively. This result was similar to the original ligand with stable conformation and strong binding energy in protein. Conclusion: The two active components of Spatholobi Caulis play an anti-osteoporosis role by inhibiting SRC and CTSK proteins. Therefore, elucidating the mechanism of action of Chinese herbal medicine by identifying components or targets is an effective and comprehensive strategy.