Exploring the pharmacological mechanism of Glycyrrhiza uralensis against KOA through integrating network pharmacology and experimental assessment.

Knee osteoarthritis (KOA), a major health and economic problem facing older adults worldwide, is a degenerative joint disease. Glycyrrhiza uralensis Fisch. (GC) plays an integral role in many classic Chinese medicine prescriptions for treating knee osteoarthritis. Still, the role of GC in treating KOA is unclear. To explore the pharmacological mechanism of GC against KOA, UPLC-Q-TOF/MS was conducted to detect the main compounds in GC. The therapeutic effect of GC on DMM-induced osteoarthritic mice was assessed by histomorphology, µCT, behavioural tests, and immunohistochemical staining. Network pharmacology and molecular docking were used to predict the potential targets of GC against KOA. The predicted results were verified by immunohistochemical staining Animal experiments showed that GC had a protective effect on DMM-induced KOA, mainly in the improvement of movement disorders, subchondral bone sclerosis and cartilage damage. A variety of flavonoids and triterpenoids were detected in GC via UPLC-Q-TOF/MS, such as Naringenin. Seven core targets (JUN, MAPK3, MAPK1, AKT1, TP53, RELA and STAT3) and three main pathways (IL-17, NF-κB and TNF signalling pathways) were discovered through network pharmacology analysis that closely related to inflammatory response. Interestingly, molecular docking results showed that the active ingredient Naringenin had a good binding effect on anti-inflammatory-related proteins. In the verification experiment, after the intervention of GC, the expression levels of pp65 and F4/80 inflammatory indicators in the knee joint of KOA model mice were significantly downregulated. GC could improve the inflammatory environment in DMM-induced osteoarthritic mice thus alleviating the physiological structure and dysfunction of the knee joint. GC might play an important role in the treatment of knee osteoarthritis.

Liquiritin reduces chondrocyte apoptosis through P53/PUMA signaling pathway to alleviate osteoarthritis.

AIMS: The main pathological features of osteoarthritis (OA) include the degeneration of articular cartilage and a decrease in matrix synthesis. Chondrocytes, which contribute to matrix synthesis, play a crucial role in the development of OA. Liquiritin, an effective ingredient extracted from Glycyrrhiza uralensis Fisch., has been used for over 1000 years to treat OA. This study aims to investigate the impact of liquiritin on OA and its underlying mechanism. MATERIALS AND METHODS: Gait and hot plate tests assessed mouse behavior, while Micro-CT and ABH/OG staining observed joint morphological changes. The TUNEL kit detected chondrocyte apoptosis. Western blot and immunofluorescence techniques determined the expression levels of cartilage metabolism markers COL2 and MMP13, as well as apoptosis markers caspase3, bcl2, P53, and PUMA. KEGG analysis and molecular docking technology were used to verify the relationship between liquiritin and P53. KEY FINDINGS: Liquiritin alleviated pain sensitivity and improved gait impairment in OA mice. Additionally, we found that liquiritin could increase COL2 levels and decrease MMP13 levels both in vivo and in vitro. Importantly, liquiritin reduced chondrocyte apoptosis induced by OA, through decreased expression of caspase3 expression and increased expression of bcl2 expression. Molecular docking revealed a strong binding affinity between liquiritin and P53. Both in vivo and in vitro studies demonstrated that liquiritin suppressed the expression of P53 and PUMA in cartilage. SIGNIFICANCE: This indicated that liquiritin may alleviate OA progression by inhibiting the P53/PUMA signaling pathway, suggesting that liquiritin is a potential strategy for the treatment of OA.