Glabridin mitigates osteoarthritis progression through modulation of the PI3K/AKT/FOXO3A autophagy axis

Osteoarthritis (OA) is a common degenerative joint disorder marked by the breakdown of cartilage and disrupted cellular balance. While Glabridin (Gla) has shown properties that are anti-inflammatory and antioxidant, the exact therapeutic mechanism of Gla in the context of OA is not well understood. The goal of this study is to pinpoint and validate the key molecular pathway through which Gla provides protection against the advancement of OA.

This study aims to investigate the molecular mechanisms by which Gla regulates extracellular matrix (ECM) metabolism in chondrocytes, revealing critical targets and signaling pathways that mediate its therapeutic impact on osteoarthritis (OA) progression.

We used a multi-faceted approach, beginning with an integrated analysis of network pharmacology and RNA sequencing to predict Gla's key molecular targets and signaling pathways. We then performed molecular docking and surface plasmon resonance (SPR) to validate a direct physical interaction between Gla and FOXO3A. The functional consequences were confirmed in human chondrocytes using qPCR, Western blotting, immunofluorescence, and an autophagic flux reporter. We established the central role of FOXO3A by demonstrating that its siRNA-mediated knockdown abolishes Gla's effects. Finally, we assessed Gla's therapeutic efficacy in a mouse model of ACLT-induced OA using histological staining and OARSI scoring.

Our results indicate that Gla mitigates IL-1β-induced ECM degradation by modulating the PI3K/AKT/FOXO3A axis. Gla directly binds FOXO3A, promoting its dephosphorylation and nuclear translocation to activate autophagy-related genes. Local administration of Gla significantly attenuated OA progression in vivo, as reflected by reduced cartilage degeneration and improved OARSI scores. Inhibition of autophagy with 3-MA exacerbated OA pathology, an effect partially reversed by Gla.

Our study demonstrates that Gla protects chondrocytes and attenuates OA progression by directly targeting FOXO3A and activating the autophagy pathway. This mechanism highlights the potential of Gla as a novel disease-modifying agent for osteoarthritis.