Osteoarthritis (OA) is a common degenerative joint disorder that affects joint function, mobility, and pain. The release of proinflammatory cytokines stimulates matrix metalloproteinases (MMPs) and aggrecanase production which further induces articular cartilage degradation. Hypertrophy-like changes in chondrocytes are considered to be an important feature of OA pathogenesis. A Glycyrrhiza new variety, Wongam (WG), was developed by the Korea Rural Development Administration to enhance the cultivation and quality of Glycyrrhizae Radix et Rhizoma (licorice). This study examined the regulatory effect of WG against hypertrophy-like changes such as RUNX2, Collagen X, VEGFA, MMP-13 induction, and Collagen II reduction induced by IL-1β in SW1353 human chondrocytes. Additionally, in silico methods were performed to identify active compounds in licorice to target chondrocyte hypertrophy-related proteins. WG showed inhibitory effects against IL-1β-induced chondrocyte hypertrophy by regulating both HDAC4 activation via the PTH1R/PKA/PP2A pathway and the SOX9/β-catenin signaling pathway. In silico analysis demonstrated that 21 active compounds from licorice have binding potential with 11 targets related to chondrocyte hypertrophy. Further molecular docking analysis and in vivo studies elicited four compounds. Based on HPLC, isoliquiritigenin and its precursors were identified and quantified. Taken together, WG is a potential therapeutic agent for chondrocyte hypertrophy-like changes in OA.
Prolonged inflammation results in chronic diseases that can be associated with a range of factors. Medicinal plants and herbs provide synergistic benefits based on the interaction of multiple phytochemicals. The dried root of Scutellaria baicalensis Georgi and its compounds possess anti-inflammatory, anti-oxidative, and anticancer effects. Processing is a traditional method to achieve clinical benefits by improving therapeutic efficacy and lowering toxicity. In this study, we investigated the anti-inflammatory and anti-oxidant effect of processed Scutellaria baicalensis Georgi extract (PSGE) against lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Data using Griess assay and ELISA showed that PSGE decreased nitric oxide and prostaglandin E2 (PGE2) levels against LPS. PSGE treatment up-regulated 15-hydroxyprostaglandin dehydrogenase (PGDH), while cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1 expression did not change. Interestingly, PGE2 inhibition was regulated by prostaglandin catabolic enzyme 15-PGDH rather than COX-2/mPGES-1, enzymes essential for PGE2 synthesis. Additionally, PSGE-suppressed LPS-induced IL-6 and TNF-α production through NF-κB signaling. NF-κB release from an inactive complex was inhibited by HO-1 which blocked IκBα phosphorylation. The ROS levels lowered by PSGE were measured with the H2DCFDA probe. PSGE activated NRF2 signaling and increased antioxidant Hmox1, Nqo1, and Txn1 gene expression, while reducing KEAP1 expression. In addition, pharmacological inhibition of HO-1 confirmed that the antioxidant enzyme induction by PSGE was responsible for ROS reduction. In conclusion, PSGE demonstrated anti-inflammatory and anti-oxidant effects due to NRF2/HO-1-mediated NF-κB and ROS inhibition.