Loganin inhibits the ROS-NLRP3-IL-1β axis by activating the NRF2/HO-1 pathway against osteoarthritis

Abstract

Loganin (LOG), a bioactive compound derived from Cornus officinalis Siebold & Zucc, has been understudied in the context of osteoarthritis (OA) treatment. In this study, we induced an inflammatory response in chondrocytes using lipopolysaccharide (LPS) and subsequently treated these cells with LOG. We employed fluorescence analysis to quantify reactive oxygen species (ROS) levels and measured the expression of NLRP3 and nuclear factor erythropoietin-2-related factor 2 (NRF2) using real-time quantitative polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence (IF) techniques. Additionally, we developed an OA mouse model by performing medial meniscus destabilization (DMM) surgery and monitored disease progression through micro-computed tomography (micro-CT), hematoxylin and eosin (H&E) staining, safranin O and fast green (S&F) staining, and immunohistochemical (IHC) analysis. Our results indicate that LOG significantly reduced LPS-induced ROS levels in chondrocytes, inhibited the activation of the NLRP3 inflammasome, and enhanced NRF2/heme oxygenase 1 (HO-1) signaling. In vivo, LOG treatment mitigated cartilage degradation and osteophyte formation triggered by DMM surgery, decreased NLRP3 expression, and increased NRF2 expression. These findings suggest that LOG has a protective effect against OA, potentially delaying disease progression by inhibiting the ROS-NLRP3-IL-1β axis and activating the NRF2/HO-1 pathway.