Fraxetin inhibits interleukin-1β-induced apoptosis, inflammation, and matrix degradation in chondrocytes and protects rat cartilage in vivo

Qing Wang; Di Zhuang; Wenchang Feng; Bitao Ma; Liping Qin; Lilun Jin

doi:10.1016/j.jsps.2020.09.016

Fraxetin inhibits interleukin-1β-induced apoptosis, inflammation, and matrix degradation in chondrocytes and protects rat cartilage in vivo

Saudi Pharm J. 2020 Dec;28(12):1499-1506. doi: 10.1016/j.jsps.2020.09.016. Epub 2020 Sep 25.

Authors

Qing Wang¹, Di Zhuang¹, Wenchang Feng¹, Bitao Ma¹, Liping Qin¹, Lilun Jin¹

Affiliation

¹ Department of Traditional Chinese Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.

Abstract

Osteoarthritis (OA) is a disease characterized by degeneration of the joint complex due to cartilage destruction. Fraxetin, a widely used and studied coumarin compound extracted from a traditional Chinese herb (Qin Pi), has shown anti-inflammatory and antioxidant properties, but its effects on OA have not been studied. In the present study, western blotting, immunofluorescence, and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) were used to evaluate the effects of fraxetin on IL-1β-induced apoptotic activity, inflammatory responses, and catabolism in rat chondrocytes. The results showed that fraxetin prevented IL-1β-induced apoptosis of chondrocytes and inhibited inflammatory mediator release by regulating the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor (NF)-κB pathway in chondrocytes. Additionally, fraxetin suppressed the upregulation of matrix metalloproteinase 13 (MMP13) and degradation of collagen II in the extracellular matrix (ECM). Moreover, the effects of fraxetin in vivo were assessed in a monosodium iodoacetate (MIA)-induced rat model of OA using hematoxylin and eosin (H&E) and Safranin O-fast green staining and magnetic resonance imaging (MRI). The results showed that fraxetin protected the cartilage against destruction. In conclusion, fraxetin could be a potential therapeutic for OA.

Keywords: BSA, bovine albumin serum; CCK-8, cell counting kit-8; Catabolism; DAMP, damage-associated molecular pattern; DAPI, 4,6-diamidino-2-phenylindole; ECL, enhanced chemiluminescence; ECM, extracellular matrix; Fraxetin; H&E, hematoxylin and eosin; HRP, horseradish peroxidase; IL, interleukin; IL-1β; IgG, immunoglobulin G; Inflammation; IκBα, inhibitor of NF-κB-α; MIA, monosodium iodoacetate; MMP, matrix metalloproteinase; MRI, magnetic resonance imaging; MyD88, myeloid differentiation primary response 88; NF, nuclear factor; OA, osteoarthritis; Osteoarthritis; PBS, phosphate buffered saline, PMSF, phenylmethanesulphonyl fluoride; PRR, pattern recognition receptor; RIPA, radio-immunoprecipitation assay; SD, Sprague-Dawley; SDS-PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis; SPF, specific pathogen free; TLR, Toll-like receptor; TLR4/MyD88/NF-κB signaling; TNF-α, tumour necrosis factor; TUNEL, TdT dUTP nick-end labeling; TdT, terminal deoxynucleotidyl transferase.