Network Pharmacology-Based Prediction and Verification of the Potential Targets of Pinoresinol Diglucoside for OA Treatment

OBJECTIVE: This study aimed to explore the effects and related mechanisms of pinoresinol diglucoside (PDG) on osteoarthritis (OA) via a combination of pharmacology and animal experiments. METHODS: Traditional Chinese Medicine Database and Analysis Platform (TCMSP) Drugbank, Online Mendelian Inheritance in Man, and GeneCards databases were used to predict the putative targets of PGD against OA. A protein protein interaction (PPI) network was constructed in STING database to analyze the interaction network of these targets. Enrichment analysis was performed with DAVID database. The OA model was built by anterior cruciate ligament transection and then injected with PDG for 5 weeks. Hematoxylin and eosin (HE) staining and safranin-fixed green staining were used to evaluate the pathological change. ELISA was applied to measure the serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Immunohistochemistry was employed to detect the protein levels of kinase B (AKT), BAX, Bcl2, matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinases 1 (TIMP-1), and phosphatidylinositol 3 kinase (PI3K) in knee cartilage tissues. RESULTS: Seventy-one key targets were identified, including AKT1, epidermal growth factor receptor, SRC, estrogen receptor 1 (ESR1), and MMP9. Enrichment analysis revealed a series of pathway related to cancer, PI3K-Akt signaling pathway, and proteoglycans in cancer. Animal experiments showed that PDG alleviated the abnormal histomorphological changes of OA; suppressed TIPM, serum IL-1β, IL-6, and TNF-α levels, and PI3K and AKT activation; and increased MMP-1 expression and Bcl2/Bax ratio. CONCLUSION: PDG has a cartilage-protecting effect associated with PI3K/AKT signaling pathway in rabbit with OA and therefore might serve as a potential agent for the treatment of this disease.