Therapeutic Effect of Ethanol Extract of Propolis Against Osteoarthritis in a Mouse Model via Modulation of NF-κB and Hippo Signaling Pathways.

Osteoarthritis (OA), a chronic degenerative joint disease, leads to disability and increases the health burden. This study identified the chemical components in the ethanol extract of propolis (EEP) and investigated its effects and mechanism on monosodium iodoacetate-induced OA in mice. Three phenolic acid esters, alongside 16 flavonoids and their derivatives, were tentatively characterized in EEP using HPLC-MS, and four main components were quantified. EEP treatment alleviated pathological changes in articular cartilage and reduced serum CTX-II levels in OA mice. Network pharmacology and molecular docking predicted that pro-inflammatory cytokines (e.g., TNF-α) and apoptosis-related factors (e.g., Bcl-2) could be key targets for propolis treatment of OA-related diseases. Subsequently, EEP decreased serum TNF-α, IL-1β, and IL-6 levels; increased the mRNA expression of Bcl-2; and reduced the mRNA expression of Caspase 8 and Bax in OA mice knee joints. Meanwhile, EEP decreased the mRNA expression of extracellular matrix-degrading enzymes in knee joints. Furthermore, through a combination of molecular docking, molecular dynamics simulations, RNA-seq, qRT-PCR, and Western blot assays, this study confirmed that EEP alleviated OA through regulating NF-κB and Hippo signaling pathways in the affected joints. These findings offer scientific evidence for the use of propolis in OA treatment.