Integrated LC-MS/MS, Network Pharmacology, and Experimental Validation Reveal the Mechanism of Eucommia Ulmoides...

Eucommia ulmoides (EU) is widely used to treat osteoarthritis (OA) in China, but its pharmacological mechanism is unclear. This study aims to investigate the underlying mechanisms of the EU in treating OA using an integrative method of network pharmacology, LC-MS/MS, and experimental verification. LC-MS/MS and network pharmacology revealed that quercetin and kaempferol might be the major bioactive ingredients of EU in the treatment of OA. Two key biological processes, inflammation and cell apoptosis, as well as NF-κB signaling, were further predicted by GO and KEGG enrichment analyses. In vivo experiments using a surgical destabilization of the medial meniscus (DMM) mouse model of OA showed that EU alleviates cartilage matrix degradation and chondrocyte apoptosis in the DMM-induced OA mice by inhibition of IL-1β, TNF-α, and p-P65 expressions. In vitro experiments employing IL-1β-treated ATDC5 chondrogenic cells elucidated that EU inhibited IL-1β-induced chondrocyte catabolism through suppressing NF-κB signaling. Overall, our findings revealed that the EU attenuates OA by inhibiting inflammation-induced chondrocyte catabolism and apoptosis by suppressing NF-κB signaling. EU can be a promising anti-OA drug and deserves further investigation.